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/ 



Class 1 ~P 
Book _ ■ M Q 
Copyright ft 'ay 2- 

COPYRIGHT DEPOSIT. 



























































List of 

United States, British and 
German Patents 


Covering Compositions and Substances 
Entering into the Manufacture 
of Glass 


Compiled, by 

MOCK AND BLUM 

Patent Lawyers 
220 BROADWAY, NEW YORK, N. Y. 

Copyright, 1919, by Mock and Blum 





Table of Contents. 

Preface .. 

U. S. Patents. 1 to 111 

British Patents .. ...112 to 157 

German Patents ... .. ; ...... 158 to 164 

Index to Names of Patentees and Assignees i to vi 
Index to Subject Matter . vii to xxi 




©Cl. A 525514 


V 



MAY 16 1919 











Preface. 


The glass industry in this country has ably responded 
to the unusual demand made upon it in the last few 
years because of the conditions arising from the war, 
and it is to be expected that it will permanently pro¬ 
duce in this country articles heretofore almost ex¬ 
clusively imported. In any event conditions prevail 
ing before the war will not prevail for many years to 
come. 

This compilation of U. S., British and German 
patents has reference only to the chemical side of glass 
manufacture. The patents relate not to the machinery 
employed in connection with the manufacture of glass, 
such as glass blowing machines, but are concerned with 
the compositions and substances that enter into the 
manufacture of glass, that is, more especially with glass 
formulae. The compilation of such glass patents for 
U. S. is complete up to Jan. 1, 1919, for Great Britian 
is complete from 1855 to July 1, 1918, and for Ger¬ 
many is complete up to the end of 1914. 

Some of the topics treated of in these patents are 
as follows: 

Coating hollow objects; producing glass of various 
colors including black glass, and also glass having a 
dull lustrous appearance. 

Producing strong and tough glass, and glass resist¬ 
ant to chemicals and acids; preventing the formation 
of air bubbles in glass; producing glass suitable for 
strong bottles for containing charged waters or the 
like; producing glass that can withstand sudden changes 
of temperature; producing glass for globes or bulbs. 


The specifications of U. S. Patents have been repro¬ 
duced in full. The claims of U. S. patents still in 
force are not given in full, but the characteristic claim 
or claims are reproduced. Where it is desired to get 
copies of all the claims of the U. S. patents this can 
easily be done by remitting five cents to the Commis¬ 
sioner of Patents. 

As the U. S. glass industry has for the future deter¬ 
mined to set itself free from all foreign dominance 
and standards, it is hoped that this compilation will do 
something toward that end. 

MOCK and BLUM. 

Hugo Mock. 

Asher Blum. 

New York, March 1, 1919. 


Index of Names of Patentees and 
Assigns. 


U. S. PATENTS 


Adams . 

Ayling . 

Bellamy . 

Bernasconi . 

Bishop . 

Borchers . 

Brady . 

Brookfield . 

Burckhardt . 

Corning Glass Works . . 

Elliott . 

Enquist .. 

General Electric Co. 

Gill & Co. 

Glaeser . 

Higley . 

Hirsch . 

Hull . 

Jensen . 

Jonkergouw . 

Keck . 

Kempner . 

Knaffi.„. 

Krause . 

Macbeth . 

Macbeth-Evans Glass Co. 

Meara . 

Miller . 


Page 

. 15 

. 22,23 

. 105 

. 38 

. 97 

. 52 

. 62,64 

. 68,73 

. 52 

. 77,92 

. 88 

.......... 104 

. 85 

. 82 

. 97 

. 7 

. 24 

. 80 

. 19 

. 31 

. 19 

. 4,16,30 

. 9 

.. 41 

. 54,58,94 

54, 58,71,88, 94, 100 

. 82 

. 100 






























11 . 


Page 

Paris . 1 

Reinmann . 35 

Rosenzi . 10 

Schnelbach . 71 

Schott . 67, 70 

Schott & Gen. 67, 70 

Shepard . 7 

Sherwood . 110 

Shirley . 2,4 

Sindele . 6 

Spitzer . 20 

Stewartson . 6 

Stiefel . 77 

Sullivan . 45, 48, 77 

Taylor . 77, 92 

United Gas Improvement Co. 62, 64 

Van Fleet . 26 

Weintraub . 85 

Welz .. 18 

Western Electric Co. 105 

Wolf . 52 

Zirkon Gelesellschaft . 52 

Zsigmondy. 28 


BRITISH PATENTS 


Archereau . 121 

Balmain . 121 

Baugh . 118 

Becker . 145, 146, 155 

Bloxam . 148 

Boardman . 155 

Bohm . 137 

Bousfield . 119 

Bower . 116 

Bredel . 146,147 

British Thomson-Houston Co. 152 

Britten . 122, 124 

Brooman .. 115, 117 






































111 . 


Burckhardt . 

Butterworth . 

Cay. 

Chamblant. 

Chance. 

Chardonnet . 

Chaudet. 

Clark . 

Claus . 

Cobley . 

Colbey . 

Colton . 

Corning Glass Works 

Craig . 

Davidson . . . .. 

Davis. 

Deane . 

Destrez. 

Devillers . 

Eddy . 

Ellis . 

Elsdon . 

Emerson .. 

Eyer.. 

Farj as . 

Fleming. 

Fleury . 

Fowler. 

Garchey. 

Gatehouse. 

Grille . 

Glasgow. 

Gossage . 

Green. 

Grosse . 

Hadden . 

Hailwood. 

Hargreaves . 

Harris . 


Page 

151 

140 

136 
115 
114 

133 
118 

120, 127, 128 
131 

. ... 116,117 

129 
131 
157 
156 

134 
156 
123 
148 
146 

151 
139 
12Q 
118 

.. .. 156 

. 150 

126 

120 

118 

139, 140, 144 
131 
144 

. .. . 156 

117 
120 

137 
134 

152 
120 

130 









































IV. 


Heinzerling. 


Page 

. 123 

Herman . 


. 131,141 

Hewitt . 


. 130 

Huelser . 


. 135 

Humann . 


. 155 

Johnson . 


. . 115, 124, 132, 146 

Jonkergouw . 


. 148 

Kempner .. 


. 127 

Kersten . 


. 151 

Kew . 


. 125 

Knospel . 


. 142 

Kralik . 


. 138 

Lake. 


. 126, 128, 130 

Lewes . 


. 137 

Leuchs . 


143 

Lindemann. 


. 149 

Mackay.. . . 


. 123 

Margueritte. 


.112, 113 

Medlock. 


. 114 

Moore .. 



Morgan-Brown . 


. 129 

Moser. 


. 140 

Newton ... 


. 116,119 

Paris .. 


. 112 

Parker . 


. 118 

Parry . 


. 129,134 

Penney. 


. 118 

Prince .. 


. 121 

Pulvermacher . 


. 127 

Rhoden .. . . . 


.. 142 

Rible .. ... 


. 150 

Richardson . 


. 112,122 

Rickmann . 


. 154 

Robbins . 



Rudolf . 


. 150 

Rust . 


. 134 

Sanoscop Glas Ges. . . 


. 155 

Schanz . 


. 150 

Schulz . 

... . . 

. .... 135 









































V. 


Page 

Seemen.,... 149 

Shirley . 132 

Siemens-Schuckertwerke Ges. 153, 155 

Smith. 122 

Soc. Anonyme, etc.*. 138 

Solms-Baruth . 138 

Sower by . 126 

Standen . 132 

Stanford . 132 

Stein . 120 

Strandh . 157 

Sudre. 143 

Sullivan . 157 

Tanner. 118 

Taylor . 157 

Thierry . 143 

Timm. 147 

Vera. 123 

Vereinigte Chemische Fabriken Landaw, 

Kreidl, Heller and Co. 152, 153, 154 

Walker . 135,136 

Wallace . 124 

Walsh . 141 

Walter. 141 

Webb . 117,125 

Welden. 119 

Welsh . 134 

Welz . 136, 137 

Whitburn. 117 

William . 136 

Wilsmore. 139 

Wilson. 122 

Wirth. 126 

Wittman . 126 

Wright. 112 

Ziegenbruck. 143 

Zsigmondy . 142, 145 






































VI. 


GERMAN PATENTS 


Allendorf. 

Becker . 

Chemische Fabrik Gustrow 

Dickmann . 

Drossbach . 

Goerisch and Co. . 

Hirsch .. 

Kempner . 

Kersten . .. 

Knospel .. 

Lesmuller. 

Meurer. 

Moser . 

Rappo.. 

Richter . 

Sachsiche Glasswerke. 

Sackur .. 

Schott and Gen. 

Spitzer. 

Stock ... 

Tedesco . 

Welz . 

Yedesco.. 

Zsigmondy. 


Page 
162, 163 
161 
. . 163 

160 
160 
160 

159 

158 
162, 164 

162 

163 

161 

161 

160 
160 
161 

163 

164 

159 
164 

158 
158, 159 

159 
162 


























Vll. 


Subject-Matter Index. 


Note : This also includes the ingredients or sub¬ 
stances. These have been indexed under the names 
referred to in the respective patents, as a matter of 
convenience to the reader, so that the same substance 
or chemical compound may appear in this index under 
more than one name. Where an ingredient is men¬ 
tioned several times in a patent, it is only referred to 
once in this index for that patent. 

Page 

acidic oxids of the 4th group. 53, 153 

actinic rays, glass impervious to. 163 

agate, glass resembling . 138 

alabaster glass (see opal glass) ... 4, 35, 89, 119, 127 

alginic acid . 132 

alkali .. 29,67, 70, 116, 130, 

134, 147, 153, 164 

alkali waste . 119 

alkaline arsenites . 138 

alkaline earths. 103, 148, 158 

alkaline fluorides . 16, 132 

alkaline liquors, waste. 123, 131 

alkali meta-silicates . 151, 164 

alkaline nitrates . 139 

alkaline silicofluorides . 16, 30, 135 

alkaline sulphates . 157 

altars . 127. 

alum .. . 8, 78 

alumina . 12, 19, 26, 30, 67, 70, 83, 93, 

103, 113, 143, 148, 149, 157 

aluminates . 84, 143 

alumina biphosphate . 114 

aluminum . : . 142, 143, 152, 156,159 

aluminum hydrate .. 62, 56, 59, 95 

aluminum oxid. 29, 55, 59, 72, 77, 93, 95 

aluminum-sodium fluoride .. ... 119 

aluminum sulfate . 90 

aluminiferous mineral . 16 



























Vlll. 


Page 

amber glass. 19, 23 

ammonia . 120 

ammonium ... 152 

ammonium chloride . 120 

antimonates . 154, 156 

antimonic acid . 129 

antimony . 24, 91, 103, 105, 130, 156, 160 

antimony oxid . 29, 83, 93, 107, 156 

antimony tetroxide . 154, 156 

arc light globes . 36 

arc light, reflector for. 153 

arseniates . 25 

’ arsenic. 7, 14, 15, 25, 36, 129, 130, 134, 139 

arsenic oxid . 24, 83, 141 

arsenic, white . .,. 118, 123 

arsenious acid . .. 20, 24, 118, 138, 140, 157, 161, 162 

art, copies of works of. 3 

asbestos . 36, 152,161 

ashes . 118,161,162,163 

balusters . 127 

barium . 28, 142, 145 

barium carbonate . 5,29,91,93,115,116,117, 

122, 124, 126, 134, 142, 150 

barium chlorate . 142 

barium chloride .. 112 

barium hydrate . 29, 116, 142 

barium nitrate. 29, 125, 142 

barium oxide. 29, 77, 117, 122, 142 

barium salts . 28 

barium silicate . 116, 131 

barium silicofluoride . 116 

barium sulphate . 5,91,137,143,150 

bark, spent . 123 

barometers, glass for tubes of. 140 

baryta . 29,40,70,138,162 

baryta biphosphate. 114 

baryte sulphate . ...w . 116 

basalt ..-. 138, 151 






































IX. 





* Page 

bauxite.......... 143, 156 

benzoline . 124 

beryllium . 156 

beryllium carbonate . 149 

beryllium fluoride . 149 

beryllium oxide. 149 

bismuth . 142 

bismuth oxide. 113, 140, 161 

black glass . 7, 11,27, 127 

black enamel. 38 

bleach, spent ..2. 125 

blue enamel . 143 

blue glass . 13 ' 

bone. 159 

bone ash . 14,129,150 

bone glass . 155 

boracic solutions . 143 

boracic acid ....... !T. .. . 2, 67, 70, 154 

borax . 27, 32, 39, 42, 56, 59, 72, 83, 95, 107, 

114, 123, 126, 134, 138, 148, 156 

boric acid*. 9, 29, 158, 164 

boric anhydride . 86, 95 

boric oxide ....... 93, 153, 157 

boro-silicate . 88, 156 

boron.. . ... 155 

boron carbonate . 151 

boron fluoride. 149 

boron oxide . 149 

bottles, glass for . i ... 19, 22, 113, 122, 124, 131, 161 

bottles, utilizing .'.. 118 

brackets . 127 

brass .. 141 

bricks ... 132, 146 

brown glass .. 133 

bubbles, quartz glass free from . 146 

building blocks . 6, 132 

busts. 127 

cadmium . 150 


- 







































X. 


Page 

cadmium sulphide. 18, 136, 158, 159 

calc-spar ...134 

calcium. 142, 143, 156, 157, 161 

calcium carbonate. 63, 66, 75, 157 

calcium chloride. 112, 135, 138, 140 

calcium fluoride . 103 

calcium oxid ... 75, 111 

calcium phosphate. 128, 129, 130, 134, 142, 162 

calcium silicate . 42 

calcium-sodium-silicate .:. 97 

calcium sulphate.72, 91, 124 

carbon.. 110, 115, 123, 150, 151, 159, 161 

caustic potash. 121 

caustic soda . 118, 121 

centre pieces . 127 

ceramics. 3, 34, 140, 144, 148 

cerium..... 142, 155, 160 

cerium fluoride. 160 

cerium silico-fluoride . 160 

chalk .. 16, 32, 119, 132, 135, 137, 138, 150, 154, 156 

charcoal. 5,92, 112, 123, 135/137, 150 

chemicals, glass resistant to .. 10, 67, 70, 94, 144, 164 

chimneys, glass for. 139, 146 

China clay. 38, 95, 118, 132, 134, 156 

chlorides, decomposing . 115 

chlorides, metallic . 130, 133, 135 

chrome. 14 

chromite ... 143 

chromium. 42, 122, 150 

chromium oxide. 13, 114, 118, 132 

cinder steel . 120 

clay ... 6, 22, 23, 38, 68, 112, 113, 114, 

140, 158, 159, 161, 162, 163, 164 

clouded glass . 145 

clouding agents. 153, 154, 156, 158 

coal.15, 111, 122, 123, 129, 131, 163, 164 

coatings . 1 

cobalt.. 42, 64, 66, 156 




































XI. 


Page 

cobalt arsenio-sulphide . 114 

cobalt biphosphate . 114 

cobalt lustre . 143 

cobalt oxide. 32, 64, 66, 114, 155 

cobalt, vitrified . 3 

cobaltum . 36 

coffins. 118, 127 

coke.. 15, 97, 122, 123, 135, 147 

color filter.. 62, 64, 156 

colored glass. 106 

colored lenses . 124 

coloring agents...3, 6, 156, 162 

columns . 127 

copper. 64, 106, 130, 141, 150, 156 

copper carbonate.13, 14, 132 

copper oxide ... 6, 32, 36, 63, 114, 128, 133, 160, 134 

copper protoxide . 6 

copper-ruby glass . 160 

copper suboxide . 138 

cornices . 127 

cryolite . 4, 12, 16, 30, 72, 91, 95, 103, 

123, 126, 127, 132, 135, 150, 159 

crystal. 112, 113, 122, 146 

crystal rock . 146 

culinary purposes, glass for. 92, 157 -36 

cullet. 114, 122, 134, 135 

dark glass . 162, 163 

decolorizing glass. 24, 116, 139, 140, 

142, 160, 161, 162 

devitrified glass . 142, 146 

dishes . .. .. 36, 122, 134, 158a 

dolomite . 143 

earthenware, substitutes for. 139, 144 


earths, rare . 

electric condensers, glass for 


143 

145 


electric light bulbs. 36, 54, 57, 83, 155 

electrodes, glass for. 145 

electrolytic deposits, glass for receiving .... 145 




































xii. 

Page 

enamels. 1, 38, 80, 112, 113, 114, 116,^ 

125,. 143, 152, 153, 154, 158 

erbium. .... 155, 160 

expansion, glass having low thermal 92, 155, 157, 158 

faience, substitutes for .. 144 

feldspar. 12, 30, 45, 49, 91, 95, 103, 113, 

117, 124, 127, 142, 144, 162 

ferric borate . 43 

ferric oxide. 42, 124, 143, 147 

ferroline ....... .'. 10 

filter, light . 152 

finger bowls .. ..i. 36 

fire, glass free from. 54, 58, 78, 82, 89 

flexible glass . 132, 133 

flint. 116, 117, 121, 124, 129 

flint batch . 127 

flint glass.. 2, 3, 11, 124, 126, 129 

fluorid... 55, 59, 91 

fluorin.\ . 30, 56, 60, 78, 95, 103 

fluorspar. 4, 11, 56, 60, 95, 116, 122, 127, 130 

florspar . 144 

fluxes.... 126 

Fontainebleau sand . 32 

fountains ..... 127 

fusible glass..10, 115, 152 

gage-glasses . 67, 140 

galena ..... 45, 49 

gas lime ... 123 

gas tar . 121 

gas-tight joint, glass for making .. 41 

glass flux . 38 

glass gall. 145 

glass, iridescent . 127 

glass, soluble . 123, 137 

Glauber salt . 83 

glazes. 10, 80, 116, 132, 143, 156 

globes for lamps .. 36, 54, 58, 63, 65, 90, 94, 130, 136 
glucina .3.. 143 




































xiii. 


Page 

gold. 12, 28, 107, 132, 142, 143, 145, 159, 162 


gold chloride . 130, 151 

gold colored glass . 128 

gold nitrate. 130 

gold oxide . 32, 132 

gold-ruby glass . 162 

golden-yellow glass . 142 

granite . 117 

granite, glass resembling. 155 

granulite . 135 

graphite . 145, 151 

green glass ... 13, 19, 22, 27, 113, 133, 139, 142, 160 

green color, preventing in glass. 120 

greenish glass . 137, 159 

green-paint ore . 27 

grit. 120 

gum arabic . 39 

gum . 142 

gypsum. 47, 83, 151 

heavy spar . 4,127 

fiySrocliKM-ic^aci^V. . ’.f?*. 7. *..97, 112, 137 


hydrogen phosphide . 12^ 

infusorial earth . 116 

insulating glass. 22, 26, 123 

insulating joint, glass for. 41, 153 

insulators, glass for. 22, 26, 68, 73, 125, 145 

iridescent glass. 125, 126, 129 

iron. 42, 115, 122, 129, 130, 135, 

140, 141, 150, 153, 155, 161 

iron oxide. 26, 29, 122, 126, 127, 149, 155, 162 

iron peroxide . 135 

iron protoxid . 26 

jugs . 134 

kaolin. 12, 16, 70, 112, 113, 116, 120, 132 

lamp glass . 125 

lanthanum . 154, 155 

lava . 3 

lava pottery . 3 


!> (o 








































XIV. 


Pa?e 

lead. 9, 24, 35, 39, 46, 50, 142, 150 

lead glass. 45, 48, 68, 76, 87 

leaded glass . 38 

lead, red. 107, 134, 156 

lead, white . 130 

lead biphosphate. 114 

lead carbonate . 45, 80 

lead oxide . . 7, 11, 45, 48, 56, 59, 78, 80, 83, 91, 103, 
113, 115, 116, 122, 123, 130, 158, 163 

lead silicate.46, 112, 116, 131 

lead silicofluoride . 116 

lead sulfate.45, 91, 112, 114 

lead sulfid . 45, 49 

lead, white . 132 

lenses . 122, 128, 155, 156 

lepidolite . 104 

lignite . 131, 162 

lime ... 6, 7, 9, 15, 20, 29, 30, 47, 51, 67, 69, 70, 71, 
72, 76, 97, 107, 112, 113, 115, 116, 118, 120, 

121, 122, 123, 124, 128, 129, 132, 134, 136, 

139, 142, 145, 147, 148, 149, 151, 156, 162 

lime borate . 112 

lime carbonate. 114, 115, 138, 151 

lime chloride . 125 

lime glass . 68, 76 

lime nitrate . 78 

lime phosphate.4, 114, 127, 134 

lime silicate . 131 

lime sulphate . 132 

lime sulphide . 132 

limestone. 15, 19, 47, 51, 97, 99, 144 

linings . 118 

litharge .... 13, 14, 27, 45, 48, 51, 72, 103, 132, 151 

lithia. 93, 104, 157 

lithium borate. 149 

lithium carbonate .. . 149 

lithium fluoride.. 149 

looking glass. 113 


































XV. 


Page 

low-expansion glass . 88 

lustre colors . 142 

lustre ware . 143 

magnesia. 27, 31, 70, 124, 143, 149, 153 

magnesia biphosphate. 114 

magnesite .. 124 

magnesium . 143, 158, 162, 163 

magnesium carbonate. 78 

magnesium oxid . 86, 121 

magnesium phosphate . 78 

magnesium pyrophosphate. 79 

magnesium sulphate. 91 

manganese. 14, 42, 122, 127, 160, 161 

manganese binoxide or dioxide. 15, 119, 126, 149, 161 

manganese oxid. 29, 88, 118, 119, 126, 134 

manganese peroxide.119, 140, 151 

manganese sulphate . 119 

manganese sulphide . 119 

mantlepieces . 118 

marble .. 115, 123, 126, 139, 146 

marbled glass. 137 

medallions .•. 127 

meldon stone. 135 

metallic oxides. 120, 122, 132 

metallic salts .. 132 

metallic union, glass for. 10, 77, 85, 155 

metallizing glass. 127, 128 

milk glass. 4, 121, 127, 158, 159, 162 

minium. 32, 45, 48, 112, 114, 148 

mirrors, glass for. 11,151 

moldings . 127 

molybdenum . 87 

monuments .. 127 

mosaics ... • • • 3 

neodymium . 155, 160 

nickel . 24,42,64,66,139,156 

nickel arsenio-sulphide . 114 

nickelous hydrate . 140 







































XVI. 


Page 

nickel hydroxide. 161 

nickel oxid. 63, 65, 116 

nickel salts . 65 

niter. 11, 36, 46, 56, 59, 72, 91, 103, 123 

niter cake. 110 

nitrates, metallic. 130 

oats, calcined. 133 

obsidian . 10 

opal glass. 12, 30, 54, 56, 58, 119, 129, 130 

opalescent glass.16, 132, 135 

opaline glass . 138 

opaque glass. 71, 78, 132, 133, 141, 

142, 143, 150, 162 

opaque glassy flux.^. 160 

opaquing agents . 154 

optical glass. 150 

orange-colored glass. 18, 24 

orange-red glass.18, 136, 158 

orange-yellow glass. 136, 137, 159 

ornamenting glass. 143 

oxides, metallic. 120, 122, 132, 134, 160 

oxides, fixing refractory . 149 

oxides of quadrivalent elements. 163 

partitions . 141 

panels .•. 127 

paving slabs. 120 

pearlash. 11, 46, 91, 119, 123, 156, 158 

peat . 162, 164 

petroleum . 121 

pedestals . 127 

phonolite . • 19 

phosphates . 91, 114, 115 

phosphoric acid.... 9, 129 

phosphorus . 150 

pigments . 116, 144 

pink glass..13, 122, 143 

pipes, glass for making. 7, 132 

plaques. 128, 139, 146 

plates . 156 









































XVII. 


Page 

platinum. 127 

platinum chloride . 118 

ploy-phosphate . 9 

porcelain . 129, 144 

porphyry . 7 

potash. 4, 7, 9, 20, 26, 39, 95, 109, 113, 

114, 122, 127, 129, 130, 134, 151 

potash biphosphate . 114 

potash, caustic. 123 

potassa. 19,48,104 

potassium bitartrate . 134 

potassium carbonate. 3, 32, 63, 66, 115 

117, 121, 123, 143 

potassium chloride. 14, 112, 117 

potassium-magnesium-boro-silicate . 152, 153 

potassium nitrate . 4, 32, 63, 66 

potassium oxid. 77, 86, 157 

potassium silicate . 117, 119 

potassium silicofluoride . 16 

potassium sulphate . 117, 121 

praseodymium. 155, 160 

pressure, glass adapted to withstand. 19, 140 

prisms . 156 

purple glass. 118, 142, 143 

pyrolusite... 24, 147 

pyroxylin . 133 

quartz. 32, 52, 68, 85, 87, 88 

120, 121, 124, 147, 148, 151 

quartz glass . 52, 146 

radio-active glass . 150 

radium . 150 

radium carbonate . 150 

radium sulphate. 150 

red glass. 130, 134, 160, 161 

red glass . 130, 134, 143, 159 

reddish brown glass. 23 

reflectors . 125,155 

resinates.*.. 142 






































XV111. 


rock, fusible . . . 
rock, volcanic . . 
rose-red glass . 
rose-lustre glass 
rubidium .... 
ruby glass 
sal-ammoniac . 


Page 

.. 150 

............. 150 

18, 20, 24, 136, 138, 159 

. 142 

. 164 

.. 28, 105, 122, 160, 163 
. 7 


salt (NaCl) .6, 7, 56, 59, 83, 95, 97, 103, 112, 

116, 117, 129, 130, 135, 142 

.salt cake ..... 22, 23, 83. 129 

saltpetre. 19, 25, 119, 139, 141, 156, 160 

Samarium . 155 


sand ... 4, 6, 10, 11, 15, 16, 22, 23, 30, 32, 36, 45, 56 
60, 63, 66, 72, 78, 83, 91, 93, 95, 97, 99. 101, 


103, 107, 113, 114, 115, 116, 117, 119, 120, 

122, 123, 126, 127, 129, 130, 131, 132, 134, 

135, 137, 138, 141, 145, 147, 148, 151, 162 


sand, purifying. 117 

sandstone. 124 

sawdust. 15, 123, 151 

scoriae . 140 

selenates . 20, 24, 138, 139, 159 

selenites..... 20, 24, 138, 139, 159 

selenium .. 18, 20, 25, 107, 131, 137, 139, 

140, ISO, 158, 159, 160, 161 

shades, glass for.. . 125, 155, 156 

shale... 7, 156 

sheets, glass. 122 

silex... 83, 124 


silica ..... 7, 9, 19, 20, 26, 39, 48, 53, 68, 77, 86, 93, 
97, 99, 105, 112, 113, 116, 118, 121, 126, 127, 
131, 138, 142, 143, 145, 148, 149, 150, 151, 
152, 153, 156, 157. 


silica, soluble. 121 

silicates... 26, 124, 131, 137, 142 

silicic acid. 17, 29, 31, 67, 73, 142, 165 

silicon hydrate. 120 

silicon sulfide. 121 


silicious residue from gold and silver ore ... 117 






























XIX. 


Page 

s ‘lver. 129, 142, 150, 159 

silver chloride . 130, 138 

silver nitrate . 130 

silver sulphate.. 163 

silver sulphide. 163 

sinks..'. . . . 118 

slabs . 6, 118, 122, 127, 132 

slag .. 3, 7, 23, 116, 120, 122, 126, 129, 131, 140, 147 

slate . 6 

slate refuse . 134 

smelting raw materials with the electric arc . 146 

soap lime.. 123 

soda .... 4, 6, 9, 19, 26, 30, 36, 46, 56, 59, 67, 83, 91. 

101, 112, 113, 114, 119, 122, 126, 127, 132, 

138, 139, 146, 162. 

soda ash. 7, 72, 78, 103, 111, 122, 131, 134 

soda biphosphate.;. 114 

soda, caustic . 120, 123 

soda glass . 42 

soda lime . 123 

sodium alginate .. . . .. 132 

sodium-aluminum-fluoride . 155 

sodium bicarbonate... 11, 27, 151 / 

sodium-boro-silicate glass.. 157 

sodium carbonate .... 2, 16, 27, 32, 37, 72, 97, 111 

115, 121, 126, 132, 135, 148, 152, 154, 156 

sodium fluoride. 16, 103 

sodium fluo-silicate . 162 

sodium hydrogen sulfate . 112. 

sodium hydroxide. 152 

sodium hyposulphite . 115 

sodium-magnesium-boro-silicate . 86, 152, 153 

sodium nitrate. 107, 119, 126, 134 

sodium oxid. 43, 77, 86, 93, 153, 158 

sodium selenite. 20, 159 

sodium silicate. 42, 117, 119, 124, 129 

sodium silicofluorid. 16, 17, 30, 95, 135 

sodium sulphate. 15, 19, 22, 45, 111, 115, 

119, 121, 123, 135, 138 

































XX. 


Page 

sodium sulphite. 21, 25, 83, 116, 130 

stained glass.,. . . 122, 128, 132, 136, 145, 150 


137, 


127 

120 

140 

155 

146 

150 

152 

133 

114 

142 

125 

131 


133, 


statues . 

steatite . 

stone .• .. 

stone, glass resembling. 

stoneware . ./..,. 

stoppers, glass for. 

strengthening glass objects. 137, 

strontia . 

strontia biphosphate . 

strontium... 

strontium nitrate. 

strontium silicate. 

strontium sulphate. 91, 103, 114, 123, 124 

sulphates, reducing .. 115 

sulfur .. 45, 50, 106, 

tafifee . 

talc .• •. 

talcum . 

tanner’s lime. 

temperature, glass adapted to withstand sud¬ 
den changes in .... 26, 94, 140, 153, 

temperature, glass resistant to high. 

thermometers, glass for tubes of. 

thorium . 

thorium oxid. 

tiles. 6, 122, 127, 128, 132 

tin. 14, 152 

tin dichloride . 

tin dioxide.•. 

tin fluoride. 

tin monoxide. 

tin peroxide . 4, 129 

tin oxid . 107, 109, 127, 130, 163 

tin silico-fluoride .• •. 160 

titanic acid . 143, 152 

titanic oxid. 53, 149, 163 


150 

3 

120 

36 

123 


155, 157 
144 
142 

155 
163 
134 

156 
138 
134 
160 
138 






































XXI. 


Page 

titanium . 152, 162 

topaz glass. 133 

translucent glass and enamels . 71, 162 

tumblers. 134 

tungsten. 87 

ultra-violet rays, glass for absorbing. 150, 155 

uranium.12, 116, 126 

uranium oxid. 114, 132, 133, 137, 159 f SV 

uranium salt . 133 

urns ... 3, 127 

vases. 3, 6, 36, 127, 128, 134 

ventilators, glass for . 125 

vermilion glass.• •. 142 

vessels. 139 

vitriol, calcined . 3 

wainscoting . 127 

walls . 146 

walls, covering. 140 

wash hand basins . 118 

washstands . 146 

waste glass. 140, 141, 144 

water ..... 26, 31, 97 

water gauges, glass for tubes of. 142 

white glass .. 54 

window glass . 97, 113 

witherite . 5, 127 

wood . 137 

X-rays, glass transparent to. 149 

yellow glass . 12, 126 

zaffre . 127 

zinc. 20, 24, 130, 138, 142, 155, 156 

zinc baryta . 124 

zinc biphosphate . 114 

zinc oxid . . 70, 80, 95, 113, 116, 117, 122, 127, 143 

zinc silicate . 14, 112, 131 

zinc sulphate . 91, 114, 149 

zircon. 154 

zirconium . 142, 152, 156 

zirconium oxid . 53, 152, 163 




















































■ 


' 

. 



































' 

























































































































- 



















































































































UNITED STATES PATENTS. 


No. 7,145. Improvement in the Composition for 
Enameling Hollow Ware. Paris and Paris, Mar. 
5, 1849. 

Our invention consists of a new and useful com¬ 
position for coating articles made of either wrought 
or cast iron, so as to keep off the atmosphere and 
other fluids and matters which would cause the iron 
to oxidize. 

In order that our invention may be most fully 
understood and readily carried into effect we will pro¬ 
ceed to describe the means pursued by us. 

In the first instance the articles to be coated with 
this new composition are, whether made of sheet- 
iron in the form of vessels, trays, pipes, or otherwise, 
to have their surfaces cleansed by dilute acid, as is 
well understood, and dried, and then a coating of gum 
dissolved in water is to be laid on the surfaces by 
means of a brush or otherwise, and then the vitreous 
composition is to be sifted all over the surfaces. The 
nature of this composition wilL be described. The 
article is then to be introduced into a heated oven or 
retort (212° to 300° of Fahrenheit) to be dried, and 
when dry the article is to be removed into another re¬ 
tort heated to a bright red heat till the glassy composi¬ 
tion or vitreous matter melts on the surface,, which 
will readily be seen by looking through a hole in the 
cover of the retort or oven. The article is then to be 
removed into a close chamber or covered over with a 
cover to exclude as much as may be the action of the 
atmosphere till the article is cooled down. If on ex¬ 
amination the coating is imperfect another is to be 
added in like manner to the first. 


2 


The vitreous composition which we use is as follows: 
One hundred and thirty parts of flint glass reduced 
to powder; twenty and one-half parts of carbonate of 
soda; twelve parts of boracic acid. These matters, 
being intimately mixed, are to be placed in a glass- 
maker’s crucible and melted. The same is then to be 
drawn off and cooled and then broken down into fine! 
powder, which is to be sifted through a fine sieve—say 
seventy holes to the inch—and this powder is to be ap¬ 
plied as before described. We would remark that al¬ 
though we believe the above to be the best vitreous 
composition tor the purpose, we do not confine our- 
seLves to the above-mentioned proportions therefor, as 
the same may be varied. 

It is important in preparing the vitreous composi¬ 
tion that it should be free from foreign matter. For 
this purpose we employ hardened steel stampers for 
crushing the same into powder, and before employing 
the crucible we cause it to be coated with glass by 
applying gum water to the inner surface of the crucible, 
and then dusting over the powder of glass, and after 
the same has been well dried we cause the same to be 
heated gradually up to the heat which fuses the glass, 
by which the surface of the crucible will be coated 
with glass, and will thus when used prevent impuri¬ 
ties from the crucible getting mixed up with the glass 
or vitreous mixture melted therein. 

If it be desired that the surfaces of the iron should 
have a colored vitreous composition applied thereto, 
then we cause it first to be coated with the composi¬ 
tion above explained and afterward we apply a further 
coating of colored glass composition to the whole or 
parts of the surface as may be desired. 


No. 204,384. Improvement in the Manufacture of 
Glass from Lava. Shirley, May 28, 1878. 
i My invention relates to an improvement in the 
manufacture of glass; and it consists in adding to flint 



3 


glass, as a flux, lava or volcanic slag in suitable pro¬ 
portions, so as to produce a glass which is capable 
of being bLown, and which, when robbed of its glaze 
by the bath or other suitable treatment, will present 
a dull lusterless appearance, so as to adapt it especially 
for the imitation of antique ceramics, mosaic and lava 
pottery ware, and cheap reproductions of the works 
of ancient masters, as will be more fully described 
hereafter. 

In the manufacture of my glass, I take seven parts 
of clear flint batch, and add thereto one part car¬ 
bonate of potash or its equivalent and two parts of 
lava or volcanic slag. This slag, being mixed with 
vitreous impurities, mixes with and colors the mass 
so as to produce various tints and colors, which may 
be varied according as the proportions of the above 
ingredients are changed. When the melted mass is 
in proper condition for working, it is blown or Other¬ 
wise molded into any shape that may be preferred, 
but is especially adapted for making copies of an¬ 
tique vases and urns and copies of works of art. 

If desired, regular glass, except clear flint and plain 
white or opal glass, which decolorizes the coloring 
mixture, may be used and colored with the neces¬ 
sary chemicals to produce the required and va¬ 
rious colors, and to render the same opaque either 
by coating or backing with such dense coloring mat¬ 
ter as vitrified cobalt, taffee, calcined vitrol, or their 
requisite equivalents for the several colors required. 
These substances are used as a substitute for the lava. 

As the various articles produced will have a glaze; 
and newness of appearance that unfit them to repre¬ 
sent ancient works of art, they are subjected to the 
action of a suitable bath or any other process known 
to the art, whereby the glazing is entirely removed, 
and only a dull lusterless appearance is left. Should 
it be desired to have the glaze remain upon certain 
parts, these parts may be protected from the action ofi 



4 


the bath in any suitable manner, or these parts may 
be afterward reglazed by any suitable compound. 
Upon these parts may be engraved any suitable figure 
or design, or be fixed upon the parts in colors and 
fused to the surface. Gold and gilt decorations of all 
kinds can also be applied, and gold can be placed in 
the indented lines so as to produce a very handsome 
effect. 

By thus mixing lava and glass, I produce a new 
compound which is capable of being blown as readily 
as glass itself, so that any form that is capable of 
being formed in that manner can be reproduced very 
rapidly. Instead of carbonate of potash, any other 
flux may be used, or a flux may be entirely done away 
with, if so preferred. 

No. 210,331. Improvement in the Manufacture of 
Milk or Alabaster Glass. Kempner, Nov. 26, 
1878. 

The object of the present invention is to dispense 
with the use of whitening materials heretofore em¬ 
ployed in the manufacture of the kind of glass known 
as “milk glass,” “fusible porcelain,” “alabaster glass,” 
“cryolite glass” or “opaline,” these materials being 
generally phosphate of lime, peroxide of tin and cryo¬ 
lite. 

In carrying out my invention, I combine with the 
ordinary glass materials—soda, potash and sand—a 
mixture consisting of feldspar, fluor spar and heavy 
spar, or instead of the latter, witherite, in the mannefl 
and proportions hereinafter mentioned. 

The mixture generally used and added to the glass 
materials, and fused therewith, consists of feldspar, 
twenty to seventy-eight parts; fluor spar, seventeen 
to sixty parts; and heavy spar, five to forty parts: 
One hundred parts of this mixture are added to the 
glass mass, consisting of ten to seventy parts weight 



high grade soda, or fifteen to one hundred parts 
weight of potash, and seventy to three hundred parts 
weight of sand. 

In the fusion of the materials it is advisable to main¬ 
tain the soda scum in a stable state, and to regulate 
the greater or less consistency of the mass by increas¬ 
ing or lessening the scum which collects at the rim 
of the fusing pot. The admixture of heavy spar 
(BaS0 4 ) will increase the density and polish of the 
glass; but care must be taken that the glass is not 
made too dense by a too large use of the heavy 
spar. It will be found that four parts weight of 
heavy spar are proportioned to five parts weight of 
soda, or six and a half parts weight of potash, iri 
order to produce the most satisfactory quality of glass 
possessing the requisite characteristics of density, 
polish and high refracting power. 

Glass produced in the manner mentioned at once 
possesses the required milky or semi-translucent ap¬ 
pearance, and in the molding, blowing or other 
manipulation thereof it does not require to be re¬ 
warmed, as it cools or sets less rapidly than glass 
made in the ordinary manner. 

I may state that I use the ordinary decoloring means 
employed in processes for producing glass of the pres¬ 
ent description; and, furthermore, I add charcoal to 
five to six parts of the heavy spar. 

I aLso propose to employ, instead of this last- men¬ 
tioned material, and in connection with the other in¬ 
gredients heretofore mentioned, the material known 
as “witherite” (BaC0 3 ) in the same proportions as 
the heavy spar is used. Three parts weight of 
witherite are proportioned to five parts weight of soda, 
or six and a half parts weight of potash. When 
witherite is employed it will not be necessary to use 
the charcoal as above mentioned. 


6 


No. 270,991. Compound for the Manufacture of 
Glass. Sindell and Stewartson, Jan. 23, 1883. 

This invention relates to certain improvements in 
the manufacture of glass, and it has for its objects 
to provide an improved verifiable composition of mat¬ 
ter, and to produce a new article of manufacture, 
which besides possessing the characteristics of glass, 
will be more solid and less brittle, and will be adapted 
to many purposes for which the ordinary glass is not 
applicable. 

Our improved composition consists of sand, soda, 
clay, lime and salt. These, in a finely divided state, 
are thoroughly mixed and commingled, and are melted 
together, either in a furnace or in the usual glass- 
pots heated in the ordinary glass furnace until a 
homogeneous fluid compound is produced. When thus 
mixed, melted and combined, coloring materials— 
such as the protoxide of copper, black oxide of cop¬ 
per, or other mineral oxides—are added to the mass to 
produce the desired tint or color. 

In carrying out our invention we have found the 
ingredients in the following proportions to answer 
well for general purposes, viz: sand, one hundred 
parts; soda, fifty parts; clay, one hundred parts; lime, 
twenty-five parts; salt, twenty-five parts. These, as 
before stated, are thoroughly mixed and melted in a 
proper furnace or crucibles, and when melted the 
materials to impart color to the mass are added, as 
before mentioned, and the whole is worked subse¬ 
quently, in the same manner as ordinary glass, for the 
formation of various articles by blowing, moulding, 
casting, and otherwise. The material thus produced 
may be conveniently formed into building blocks, 
ornamental vases, slabs, tiles, and, in fact, may be ap- 
plied,to all purposes to which stone and glassware have 
heretofore been applied. 

Slate in combination with verifiable compounds has 
been heretofore employed in the manufacture of glass. 


7 


but such will not produce the variety of glass that we} 
obtain by our invention, and we make no claim to 
glass having slate as an ingredient. 

No. 285,436. Composition of Matter for the Manu¬ 
facture of Glass, Shepard, Sept 25, 1883. 

A black shale found in the lower coal measure, 
generally above No. 3 coal vein (Pennsylvania Geo¬ 
logical Survey), and elsewhere, one hundred parts; 
soda ash (carbonate soda), ten parts; lime (burned), 
thirty parts; salt (chloride sodium), twelve parts; 
arsenic, one-fourth part. These ingredients, pulverized 
and intimately mixed, I melt and treat as in the ordi¬ 
nary process of glass manufacture. The product is a 
very beautiful, strong, black glass, soft to work, and 
useful for all purposes for which glass is generally 
employed, not requiring the transmission of light. 

I prefer the foregoing combination; but the shale 
may be used without soda ash and with other fluxes 
and ingredients, or with these in other proportions, 
and the product will be the same or similar. 

I am aware that the manufacture of black glass 
is old; but I believe that it has never been made from 
the shale combined with the materials as above de¬ 
scribed. The advantage of my invention is the produc¬ 
tion of a superior quality of black glass at a cost 
much less than any ever before made. 


No. 288,056. Glass for the Manufacture of Water 
Drain and Sewer Pipes, Higley Nov. 6, 1883. 

My invention has for its object to produce an ex¬ 
ceedingly hard, strong and tough glass, which is especi¬ 
ally adapted as a material from which to make water 
drain and sewer pipes, and for a variety of other pur¬ 
poses, where great strength and durability are re¬ 
quired; and my invention consists in glass composed 
of silica, slag from smelting furnaces, porphyry, pot¬ 
ash, lime, rock salt, oxide of lead, sal ammoniac, and 




8 


alum mixed and fused together, as hereinafter more 
particularly set forth. 

In carrying my invention into effect I take fifty 
parts of silica, fifteen parts of slag from smelting 
furnaces, crushed or pulverized, ten parts of porphyry, 
crushed or pulverized, ten parts of potash, five parts 
of unslaked Lime, four parts of rock salt, three parts 
of oxide of lead, two parts of sal ammoniac, and one 
part of alum, and place them in a suitable receptacle 
and thoroughly mix and incorporate them together irt 
the usual manner, after which the compound thus 
formed is placed in an ordinary crucible used in mak¬ 
ing glass and fused, when it is drawn out into molds 
or worked in the same manner as ordinary glass. 

The proportions of the above-named ingredients 
may be slightly varied, if desired, without departing 
from the spirit of my invention. 

The above described glass can be made of any color 
desired by the addition thereto of any of the well 
known coloring substances adapted for the purpose. 

The employment of porphry, which is an inex¬ 
pensive ingredient, renders the glass exceedingly 
strong and tough and capable of withstanding blows 
and hard usage without fracture, besides giving it a 
brilliant appearance. The sal ammoniac and potash 
render the glass less brittle, and consequently much 
more durable than ordinary glass, while the rock salt 
accelerates the operation of fusing the ingredients to¬ 
gether and tends to prevent the formation of air bub¬ 
bles in the mass. 

Glass composed of the materials above described 
is comparatively inexpensive, as but a very small pro¬ 
portion of oxide of lead is used, which substance is 
one of the most expensive ingredients heretofore used 
in the manufacture of glass; and my improved glass 
is on this account particularly adapted for use in the 
manufacture of water drain and sewer pipes, and 
for an infinite variety of other purposes where a clean 


9 


hard surface is required combined with great strength 
and durability. 


No. 295,410. Process of Manufacturing Glass. Knaffl, 
March 18, 1884. 

My invention relates to a new process of manufact¬ 
uring glass by the use of phosphoric acid, and the 
production of a new article of glass. 

Heretofore in the manufacture of glass it has been 
necessary and the custom to use such ingredients as 
silica, boric acid, potash, soda, lime and lead. 

The object of my invention is, first to provide a 
process of manufacturing glass by the use of phos¬ 
phoric acid and dispensing with ingredients heretofore 
used in the manufacture of glass; second, to furnish, 
as a new article of manufacture, a gLass composed of 
few ingredients, having superior qualities, readily 
produced, and formed in any desired shape and easily 
amalgamated with metals. I attain these objects in 
the following manner: 

I take a quantity of boiling aqueous solution of 
ortho-phosphoric acid and add to it granulated metallic 
zinc so long as the zinc continues to dissolve with 
the development of hydrogen gas. This will form a 
mono base of zinc phosphate. This mono base of zinc 
phosphate is then neutralized with caustic baryta or 
strontium or calcium oxides or other suitable neutra¬ 
lizing agents. (I prefer, however, to use caustic 
baryta.) By this neutralization is formed the three- 
base zinc baryta phosphate. I then evaporate this 
three-base to dryness and subsequently melt it in a 
suitable vessel to a cherry-red heat, which, when in 
a fluid state, will be my new glass in a melted con¬ 
dition, and can be poured into any form or shape for 
future use, or can at once be moulded or made use of, 
the glass thus formed being a poly-phosphate, or my 
new glass. After the melted mass has hardened, it 
can by the application of heat be remelted into its 





10 


.former liquid state, to be used for any purpose, the 
heat required being* a much lower temperature than 
that required to melt glass manufactured by the oLd 
methods. 

Some of the striking advantages of my new glass 
are that it contains no silica, boric acid, potash, soda 
or lead; it is of higher luster and has greater refractive 
powers than other glass, thereby being of great value 
for optical purposes; it is perfectly white, clear and 
transparent, and can be ground and polished ; it is in¬ 
soluble in water and neutral, and can be attacked only 
by hydrochloric acid or nitric acid, and cannot be 
affected by hydrofluoric acid, as is the case with other 
glass; it is easily fusible in the flame of a candle, and 
can be made of any color; it is of such a nature that it 
can be readily amalgamated with metals, and can be 
used for glazing articles of glass or porcelain, metals, 
or other materials. 


No. 309,741. Manufacture of Obsidian Looking- 
Glasses. Rosenzi, Dec. 23, 1884. 

My invention relates to an improvement in the 
manufacture of obsidian looking-glasses, and it con¬ 
sists in the employment and use of ferroline, a ma¬ 
terial of which the composition was invented by my¬ 
self, and is protected by Letters Patent No. 244,486, 
granted to me on July 19, 1881, instead of obsidian, 
used by the Romans and Greeks in former ages for 
looking-glasses and reflectors on astronomical instru¬ 
ments. 

The obsidian is known to be a kind of glass pro¬ 
duced by volcanoes, and composed of ingredients 
similar to those employed in making and compound¬ 
ing ferroline. As described in the said patent, the 
component parts of ferroline are soda, silex, ashes, 
lime, magnesia, borax and arsenic, and the same have 
been found in obsidian. The high degree of polish 
of which the ferroline is susceptible qualifies it above 



11 


other materials for looking-glasses, and its deep black 
color gives it a peculiarly attractive appearance. The 
mass obtained by the proper intermixture of the in¬ 
gredients named is cast or blown into plates of any 
desirable form and thickness—flat, concave or con¬ 
vex—and polished and framed to fit the place it may 
be destined to occupy. 

The advantage gained by substituting ferroline for 
obsidian consists in its cheapness over the volcanic 
production and in its adaptability to all forms and 
sizes. The perfection and beauty of these looking- 
glasses can only be appreciated by examination. Noth¬ 
ing of the kind has ever been offered to the public. 
The reflections are as clear and distinct as seen in 
the brightest glass mirrors, but subdued by a tint 
that gives the reflected image a peculiar charm. Fer¬ 
roline may also be used for reflectors, and will be 
found of great brilliancy, but deprived of the glare 
reflected by metal, so offensive and injurious to the 
eye. 


No. 332,294. Manufacture of Glass and Articles 
Therefrom. Shirley, Dec. 15, 1885. 

My invention and discovery consist, first, in a new 
mixture for glass, whereby I produce a new translu¬ 
cent glass, which, when formed into articles, shows 
entirely new and beautiful effects; secondly, in new 
articles of manufacture from such glass; thirdly, in 
applying certain finishes to same, as more fully de¬ 
scribed hereinafter. 

To carry out my invention I take one of the regu¬ 
lar glass mixtures technically known as “lead” or 
“flint” glass, consisting, say, of one hundred (100) 
pounds avoirdupois white sand, thirty-six (36) pounds 
refined lead oxide, twenty-five (25) pounds of pearl 
ashes, five (5) pounds bicarbonate of soda, seven (7)^ 
pounds of niter. I make this translucent in any usual 
way, say by adding six (6) pounds of fluor spar and 



12 


' five (5) pounds of feldspar. This batch produces a 
well-known mixture for translucent or opal glass, and 
my new mixture consists in a batch of this sort, to 
which both gold and uranium, or its described equival¬ 
ents, are added, whereby a new glass is produced, as 
more fully described below. To a batch such as above 
described I usually use two pounds avoirdupois of ox¬ 
ide of uranium and one and one-half pennyweights of 
prepared gold, the whole to be thoroughly mixed and 
melted in the usual manner known to the art. The 
proportions above mentioned may be varied, if desired, 
or equivalents substituted without departing from thej 
spirit of my invention and discovery, which is the 
combination of the oxide of uranium with prepared 
gold, added to glass mixtures containing alumina, or 
its equivalent, when compounded, so as to form a 
translucent glass—for example, the fluor spar and feld¬ 
spar (both of which contain alumina) 1 may be omitted 
and cryolite and kaolin (which also contain aLumina) 
substituted in equivalent proportions, care being taken 
to prevent the body being made too dense. 

Articles of glassware when made from this melted 
mixture will have a beautiful sulphur-yellow color 
throughout when first formed, but in finishing same in 
the usual manner in which such articles are made, the 
metal or material will develop a delicate pink shade on 
the portions last finished, this color shading into the 
original yellow body color. Should it be desired, the 
workman by reheating the edges to a melting point 
can restore the original yellow color on the part so 
reheated, thus producing varied effects of color shad¬ 
ing not previously obtainable. 

My invention is the specific combination of a dis¬ 
tinctive coloring agent—such as oxide of uranium 
with prepared gold—and adding same to glass mix¬ 
tures, which form a translucent glass body and con¬ 
tain alumina, or its equivalent, this last named ma¬ 
terial having a special effect on mixtures containing 


13 


gold, controlling the sensitive action of its coloring 
property in a marked degree. One peculiarity of my 
mixture when melted is that where the color is once 
developed on the article is not sensitive to change from 
subsequent reheatings, unless the heat is carried to such 
a high degree as to partially melt the glass, and another 
peculiarity is that the pink or developed color by such 
increased heat can be reduced, and the part so reheated 
to its original yellow color, the workman taking care 
to keep the article in form by using his tools in the 
usual manner. The tint of yellow may be varied ma¬ 
terially from a very pale primrose with a slight green¬ 
ish tint to a deep sulphur yellow by increasing or 
diminishing the uranic oxide, and the pink or de¬ 
veloped color may be varied in like manner from a pale 
salmon color to a deep rose by adding to or decreasing 
the proportion of gold; but, if the latter is increased 
too much, the shades of color will not be so delicate, 
and it will prevent the reaction of the developed 
color to its original body color. Carbonate of cop¬ 
per or oxide of chrome, combined with litharge, may 
be used in lieu of the oxide of uranium with the pre¬ 
pared gold, and the above described translucent glass 
mixture and beautiful translucent glassware of other 
colors shading into each other can be produced, and 
combination of other oxides with the uranium and 
gold would give still other varieties of color, the first- 
named carbonate of copper producing ware of delicate 
greens to pale blue (shade of color being dependent on 
quality used), bodies shading purple and rose color, 
that is developed in the finishing. The chrome oxide 
and litharge produce a shade of yellowish green, shad¬ 
ing into a maroon or purple. When the mixture is 
melted in the pot, the workman will gather sufficient 
metal on his blow-iron to form the article desired, and 
proceeds in identically the same manner well known 
to the art, and as if making the same shaped article 
from ordinary flint glass, and without any care or 


14 


effort on his part the shaded effects described will 
be produced, and the article when finished will be an¬ 
nealed in the usual manner. I also produce a new 
and beautiful effect on this ware by removing the 
skin or glazing from the surface of the article, either 
entirely or in parts only of the same, by abrading same 
with a sand blast or immersing the articles in a bath 
suitable for that purpose. When desirable to retain 
the glaze on any portion, such parts are to be protected 
by a suitable cover or shield, or covered with wax 
or varnish, and the articles of this glass can be further 
ornamented by enamel colors, its resistance to heat 
without change of color rendering it specially adapt¬ 
able for this purpose, as enamel colors require a high 
heat to flux them. When carbonate of copper is used, 
the best proportion is nine ounces; for chrome and 
litharge, two ounces green oxide of chrome and ten 
pounds of lithrage well mixed with same, and it will 
also need an increase in amount of gold. The effects 
can be varied, as will be understood, by using a mixture 
of these coloring agents. 

I am well aware of the so-called “opalescent mix¬ 
tures” that change in the working,and which contain 
bone ash and also tin, in combination with arsenic, and 
that the same have been combined with coloring 
oxides to produce whites, greens and blues. Most of 
these have a flinty appearance with opalescent tints, 
and when reheated develop shaded colors from the 
body color to a white, the developed color being more 
or less opaque. These all turn in the working by cool¬ 
ing and reheating the article, and are all well known 
to the art for many years. I do not claim these; nor 
do I include manganese, which is frequently used as 
a corrector in all glass mixtures, in the term “dis¬ 
tinctive coloring oxides” for although, if used in ex¬ 
cess, it would give a body color, it would not be suit¬ 
able for practical use with gold, and is not the 
equivalent practically of uranium, copper or chrome 


15 


and lead, and would not produce a color in contrast 
with that developed from the gold, and is well known 
for many years to have been used in combination with 
gold in coloring glass. 


No. 360,840. Batch for Making Glass. Adams, 
April 12, 1887. 

My invention relates to the composition of an im¬ 
proved batch for the manufacture of glass, in which 
the sulphate of soda is used; and it consists, mainly, in 
forming the same in part of coal or sawdust. 

The composition of the batch as ordinarily used by 
me consists of sand, one hundred parts; sulphate of 
soda, forty parts; ground limestone, thirty-five parts, 
or burnt lime, twenty-seven parts; arsenic, two parts; 
coal, three parts. The coal used may be either bitumin¬ 
ous or anthracite, but I prefer the former. Saw¬ 
dust may be used instead of coal, and while not so 
good, in my opinion, is still an equivalent of the coal, 
and as such I wish it to be understood as included 
under the head of coal used in the claims. These in¬ 
gredients are all mixed together to form the batch be¬ 
fore it is put into the melting pot or hearth. The ef¬ 
fect of the coal or sawdust is to produce a prolonged 
ebullition, caused by the driving off of the volatile mat¬ 
ters, and this tends to clarify the bath. Moreover, 
the action of binoxide of manganese contained in the 
coal is to counteract the effect of the oxide of iron 
which exists as an impurity in the other ingredients. 

I do not limit myself to the exact proportions of 
the batch given, nor to the particular batch so far as 
the coal is concerned. 

I am aware that charcoal and coke have been 
used as ingredients in glass batches. My invention 
differs from this, however, in that I employ coal, saw¬ 
dust, or similar substances containing volatile hydro¬ 
carbons, which under the action of heat are converted 
into gases and produce the ebullition in the batch, 
which is the purpose of my invention to secure. 



16 


No. 468,723. Producing Opalescent Glass. Kempner, 
Feb. 9, 1892. 

This invention is a new process derived from melt¬ 
ing experiments for producing opalescent glass. Said 
experiments have demonstrated that fluorides of alka¬ 
lies alone do not produce opalescent glass, which fact 
is also established by other tests (vide Dingler’s Poly- 
technisches Journal, Vol 256, p. 361, 1885) ; that even 
cryolite produces opalescent glass only if added in a 
large proportion; that, however, silicofluorides of 
alkalies (silicofluoride of sodium or silicofluoride of 
potassium) or compounds thereof, when added in a 
relatively small quantity to a glass batch of any suit¬ 
able composition, produce an intensely opalescent 
glass. I have found that when adding to three equal 
batches of the same composition, respectively, ten 
grams of fluoride of sodium, cryolite and silicofluo¬ 
ride of sodium the first two mixtures resulted in a 
perfectly clear, white glass, but the third mixture con¬ 
taining silicofluoride of sodium in a completely milky 
opalescent glass. 

When making batches for an opalescent glass in 
glass works, the proportion of silicofluoride of alkali 
to be incorporated will naturally depend on the nature 
of the substances constituting the glass batch on the 
temperature of the furnace, and on the degree of dull¬ 
ness desired to be produced. If, for instance, in an 
ordinary cryolite opalescent glass batch consisting of 
thirty units of cryolite, forty-six units of carbonate of 
soda, twelve units of chalk and one hundred and sixty- 
five units of sand, the cryolite is replaced by twenty- 
five units of silicofluoride of sodium and eventually 
twenty units of kaolin, a glass perfectly equal to cryo¬ 
lite opalescent glass is obtained. The kaolin, however, 
is not absolutely necessary, but any other aluminifer¬ 
ous mineral may be substituted therefor, as it merely 
serves to produce a glass similar to cryolite. 


17 


Silicofluorides of alkalies may also be advantage¬ 
ously employed for enriching any opalescent glass 
batches. In the batch above referred to, for instance, 
fifteen units of the cryolite contained therein may 
be replaced by silicofluoride of alkali. The batch, 
which would then be composed of fifteen units of 
cryolite, forty-six units of carbonate of soda, twelve 
units of chalk, one hundred and sixty-five units of 
sand, and twelve and a half units of silicofluoride 
of sodium, results in an opalescent glass which is at 
least as good as if only cryolite had been employed. 
The action of the silicofluoride of alkali is quite dif¬ 
ferent from the action of a union of the ingredients 
constituting chemically the silicofluoride of alkali. 
With the exception of cryolite it is impossible, owing 
to the absolute absence of other raw material, to use 
anything but silicic acid as source of silicium. Silicic 
acid, however, melted together with bases will never 
result in anything but silicates of bases, no matter 
whether or not a fluor compound is present. For a 
combination, for instance, to silicic fluoride of sodium 
a reduction to silicium would be required, which, how¬ 
ever, is known not to occur under these circumstances. 
Consequently fluosilicates of alkalies are only ob¬ 
tained by chemical combination of fluosilicic acid with 
an alkali or by alternate decomposition in solutions, 
but never by the combination of the elements silicium, 
fluor and sodium. Especially fluosilicate of alkali 
has never yet been obtained by the action of high 
temperatures on mixtures of compounds of silicium, 
fluor, and alkali. Such colliquefactions, therefore, do 
not result in fluosilicate of alkali, as, when melting 
the said compounds together, no hyperfluoride of 
silicium is produced, while with dry heating of 
fluosilicates of metals hyperfluoride of silicium es¬ 
capes. It is just the energetic action of this gas con¬ 
stant at a high temperature on the other constituents 
of the glass bath which effects the addling. 


18 


Therefore, no hyperfluoride of silicium escapes 
when smelting together compounds of silicum, fluor, 
and alkali, the addling process, according to my 
jmethod, is totally different, as in my process the 
hyperfluoride of silicium is the most essential part. 


No. 479,689. Manufacture of Rose or Orange 
Stained Glass, Welz, July 26, 1892. 

My invention has relation to the manufacture of 
colored glass; and has for its object the provision 
of means whereby a permanent color may be imparted 
to the glass without reheating or staining by dipping 
the finished articles into glass containing gold salts. 

The invention relates more particularly to the manu¬ 
facture of colored glass the tint of which varies from 
a rose to an orange or orange-red color; and it con¬ 
sists, essentially, in the admixture with the molten 
glass of selenium or of selenium and cadmium sul¬ 
phide. If selenium alone is added and incorporated 
with the molten glass, the latter assumes a rose color, 
the depth of which can be varied by varying the pro¬ 
portion of selenium. On the other hand, the pro¬ 
portion of selenium for a given depth of color will 
depend upon the composition of the viterous mass, 
which composition differs for the various grades of 
glass. 

To distinguish the rose-colored product, I have 
called it “creme-rose” or “rose-cream.” 

If cadmium sulphide is combined with the selenium 
and the mixture added to the molten vitreous mass, the 
latter will assume a red-orange color, the shares of 
which, ranging from orange-redi to orange-yellow, 
will depend upon the proportion of cadmium sulphide 
used with the selenium, the color changing fromi 
orange-red to orange-yellow as the proportion of 
cadmium sulphide is increased relatively or the sele¬ 
nium used. In order to distinguish this product, I 
have called it “creme-orange” or “orange-cream.” It 



19 


is obvious that the proportions of these substances to 
be incorporated with the molten vitreous mass cannot 
well be given, for the reason that these will greatly 
vary, according to the depth of color to be given to 
the final product. 

The molten vitreous mass, colored as described, 
can be worked at once into any desired article, and 
does not require either reheating or staining, the color 
being also permanent. 

No. 494,636. Composition of Glass. Jensen & Keck, 
Apr. 4, 1893. ' 

Heretofore in the manufacture of glass an expen¬ 
sive item has been the English soda used as a base. 
We have discovered that by using a rock termed 
“phonolite,” which contains considerable alkalies, in¬ 
stead of quartz sand, an addition of carbonate of soda 
can be entirely dispensed with. Phonolite is found 
in considerable quantities in our country, and it con¬ 
sists more or less of sixty per cent of silica, twenty 
per cent of alumina, and fourteen to fifteen per cent 
of potassa and soda. German green glass, which un¬ 
til recently could not be made in the United States, 
is made by the addition of an average of twenty- 
two per cent of limestone to the rock “phonolite.” 
Light green or light amber glass for window glass or 
fruit jars requires with the rock an average of forty 
per cent of sulphate of soda and two per cent of salt¬ 
peter. The use of this rock “phonolite” for bottle 
glass, enables the manufacture of a very strong glass 
adapted to stand the strong pressure that champagne, 
mineral and soda-water bottles are subjected to. A 
more fluid glass than the above-described may be ob¬ 
tained by mixing the rock with ten to twenty-two per 4 
cent of natural sulphate of sodium. Of course lime¬ 
stone has to be mixed with the rock, twenty to thirty 
per cent. 



20 


No. 518,336. Making Rose-Red Glass, Spitzer, Apr. 

17, 1894. 

This invention relates to the process, discovered in 
1865 by the French chemist J. T. Pelouze, of staining 
glass in rose-red by the incorporation into the ordinary 
glass composition of free or so-called metallic seleni¬ 
um. In carrying out this process, the selenium is either 
added to the mixture of raw materials to be filled 
into the melting pot, or it is introduced into the al¬ 
ready molten mass. There are two grave objections 
to this process, namely, a great part of the costly 
selenium becomes vaporized and burned under the 
action of the high temperature prevailing in the glass 
melting furnace, and the selenium of commerce is al¬ 
ways accompanied by impurities such as copper, iron, 
&c., which interfere with the color of the glass and 
cannot be separated from the selenium except by a 
tedious process. According to my invention, these 
objections are overcome by adding either to the batch 
or to the molten glass composition consisting of silica, 
potash and lime suitable selenites or selenates instead 
of metallic or free selenium and by decomposing these 
salts by the introduction of a convenient agent after 
they have been completely dissolved in the molten 
mass. This agent may be arsenious acid, arsenite of 
soda, zinc dust, or other materials having similar ef¬ 
fect, but in general arsenious acid is preferred. When 
selenite of soda Na 2 Se0 3 and arsenious acid As 2 0 3 
are used two reactions take place. By the high tem¬ 
perature prevailing in the kiln oxygen is expelled from 
the Na 2 Se0 3 and the selenide of sodium Na 2 Se thus 
formed is, in presence of arsenious acid decomposed 
according to the following equation: 

3 Na 2 S e -j- As 2 0 3 -{- 3 S iO 2 — 3 Na 2 S i 0 3 -f- 3 S e -j- As 2 

The selenite of soda, Na 2 Se0 3 , is also decomposed by 
the silicic acid Si0 2 and the selenious acid freed there- 


21 


by is deprived of its oxygen by the arsenious acid, 
which takes place according to the following equations: 
Na 2 Se 03 +Si 0 , 2 =Na 2 Si 03 +Se 02 . 

Se 02 +As 20 3 =Se+As 2 05 . 

It is obvious however that the said salts and separat¬ 
ing agents may be introduced together. I thus re¬ 
place the easily inflammable metallic selenium by sub¬ 
stances, which are very steady under high tempera¬ 
tures, and in preparing the selenites or selenates of 
the selenium of commerce, the impurities are neces¬ 
sarily at the same time eliminated. Consequently a 
better result is obtained at less expense. 

In practice I find it preferable to use the selenites 
or selenates of alkalies or alkaline earths; it is obvious, 
however, that other salts of selenious or selenic acid 
may be used provided that the bases of these salts do 
not give a wrong color to the glass. The selenites or 
selenates chosen, which in most cases will be the 
potassic, sodaic or calcic salts, are either mixed with 
the batch or added to the molten glass mass, and in 
both cases the molten mass is well stirred up in order 
to obtain a uniform distribution therein of the dis¬ 
solved salt or salts. The separating agent may be 
arsenious acid, arsenite of soda or potash, sulphite of 
soda, &c., but in general zinc dust is preferred. The 
reducing agent is either mixed with the selenite or 
selenate or introduced separately, and in both cases 
the mass is stirred up after the addition. The selen¬ 
ium separated in this way gives the desired rose-red 
color to the glass. 

The quantity of selenites or selenates to be added 
to the glass composition or to the molten glass depends 
on the desired depth of color to be given to the glass, 
and is best found out by a preliminary experiment on 
a small scale. In most cases two or three parts by 
weight of the selenites or selenates will suffice for 
thousand parts by weight of glass. 


22 


No. 522,001. Composition For Manufacturing Glass. 
Ayling, June 26, 1894. 

The main objects of my invention are to produce 
what is generally known in glass manufacture as Ger¬ 
man green glass, to utilize for the purpose, waste or 
inexpensive materials and to produce a strong, tough 
metal suitable for bottles, battery jars, electric in¬ 
sulators, &c., and generally to improve the quality 
of glass for such articles. 

It consists of the composition of matter hereinafter 
particularly described. 

For the batch, I take clay, preferably in the form 
of pulverized or broken brick, ordinary sand, such as 
is commonly used in the manufacture of glass, and 
salt-cake (sodium sulphate), which is a by-product of 
the manufacture of hydrochloric acid, in about the 
following proportions by weight: one hundred parts 
of clay or broken brick, one hundred parts of sand 
and forty parts of salt-cake. The mixture composing 
the batch is then melted in the ordinary manner in 
crucibles or tank furnaces such as are commonly used 
for the purpose. A metal is thus produced which can 
be easily and economically worked and will produce 
glass of a uniform unvariable green and of superior 
strength and quality. 

Heretofore it has been found difficult, if not im¬ 
possible, in this country to produce with certainty, 
from inexpensive materials at least, the color known 
as German green, which is desirable for certain pur¬ 
poses such as the manufacture of certain kinds of 
bottles. With my improved composition as above de¬ 
scribed, the desired color can be invariably obtained. 
By varying the proportions of the ingredients, dif¬ 
ferent shades of green can be produced, but if the 
quantity of sand is increased, the salt-cake, which 
serves as a flux, should be correspondingly increased. 
I prefer, however, to employ the several materials 


23 


in about the proportions above stated, as I have found 
by experience that they give uniformly satisfactory, 
if not the best results. 

The clay which I have thus far employed is such 
as is found in the vicinity of Milwaukee, Wisconsin, 
from which Milwaukee cream-colored brick are made, 
but I do not wish to limit myself to this special variety 
of clay, as other kinds may serve the purpose equally 
well. Imperfect and broken brick made from suitable 
kinds of clay, are preferable when they can be had, 
because they are in better condition than the clay for 
melting. In places where brick are made extensively, 
sufficient quantities of such waste material can be had 
for little or nothing. 

Inasmuch as all of the materials entering into my 
composition are usually obtainable as waste products, 
glass can be made therefrom very cheaply and of 
excellent quality. 

No. 552,091. Composition for Manufacturing Glass. 
Ayling, Dec. 31, 1895. 

This composition is suitable for manufacturing 
“amber” bottle glass. 

This is made of one hundred and forty parts of 
sand, seventy parts of finely crushed, broken or pul- 
veriz ed furnac e s]ag, which is composed mainly of 
silicate of lime, and seventy parts of salt-cake, which 
is a by-product of the manufacture of hydrochloric 
acid and fifty parts of clay. When mixed and melted 
in the ordinary manner, this produces a strong, tough 
glass of a reddish-brown color. The most suitable 
clay is found near Milwaukee, Wis., and which is 
used to make Milwaukee cream-colored brick. The 
clay may be omitted. 





24 


No. 576,312. Means for Decoloring Glass. Hirsch, 
Feb. 2, 1897. 

For decoloring glass while in a molten state metals 
or metal compounds have been used, such, for in¬ 
stance, as antimony, nickel, zinc, lead, or the oxids of 
such metals. Furthermore, acids have been used, 
such as arsenious acid, also minerals, such as pyrolusite 
or manganese, and salts, such as saltpeter; but I am 
not aware that selenium has ever been made use of 
for decoloring glass while in a molten state. 

My invention consists in the use of selenium or 
selenium compound, such as selenite or selenate, for 
the above-mentioned purpose. 

I am well aware that selenium or selenium com¬ 
pounds have been proposed as means for coloring 
glass, and I refer to the publication of T. Pelouze in 
the Comptes Rendus, Vol. LXI, page 615, October, 
1865, and of the German Patents Nos. 63,558, 
73,348, 74,565, and 77,737. In all these publications 
it is set forth that selenium may be used for coloring 
glass either rose-red or orange color, but in no in¬ 
stance is reference made to the use of selenium or 
selenium compounds for decoloring purposes. Now, 
in view of the fact that not every known means for 
coloring glass is per se means for decoloring glass, 
and, furthermore, that not every known means for 
decoloring glass will be suitable for coloring glass, 
my invention is based on the discovery which I have 
made that selenium is in a very high degree suitable 
for the decoloring of glass. I have found by repeated 
experiments that by adding a very small quantity of 
selenium to the molten glass I may convert the glass 
of a dark shade into a white and bright glass of very 
fine appearance. The less dull the molten glass, es¬ 
pecially if materials of a better class have been used 
for its components or ingredients, the smaller may 
be the quantity of selenium for decoloring the same 


25 


and for obtaining white glass. Again, glass molten 
with potash will require a smaller addition of selenium 
than glass molten with soda or Glauber salt. I have 
found by experiments that with a quantity of glass 
for which one hundred kilograms of sand and the 
necessary quantity of flux have been used about one 
to five grams of selenium may be used for decolor¬ 
ing the glass. 

Experiments have proved that the same composi¬ 
tion of molten glass for the decoloring of which nickel 
has hitherto been used will deliver a much whiter 
glass if selenium be used for decoloring. The selen¬ 
ium may be used as metallic selenium or as a selenium 
compound or composition or in the form of a gas. 
It may be used as a selenite, that is to say, a salt com¬ 
posed of selenious acid and an alkali, or as a selenate, 
that is to say, a salt composed of selenic acid and an 
alkali. The selenite or selenate may be added to the 
dry glass frit or may be added to the molten glass 
and well stirred thereinto. When such a compound 
is used, suitable agents for setting free the selenium in 
the glass must be employed. These agents may be 
such as are well known for the freeing of the selenium 
from the selenite or selenate in the art of coloring 
glass with selenium; for example, arsenious acid or 
arseniate of sodium or potassium or sulfite of sodium. 
The said agents are added to the molten glass after 
the selenium compound has been dissolved therein. 

Another method of using the selenium; for de¬ 
coloring the glass is to add it in the form of cullets 
of glass containing selenium. 

It may be preferable in some cases to cause a pre¬ 
liminary decoloring of the molten glass or a simultan¬ 
eous decoloring of the same by adding other decolor¬ 
ing agents to the molten glass, such, for instance, as 
metallic nickel or oxid of nickel, saltpeter, or arsenic, 
and to obtain the higher degree of transparency or 
whiteness by means of adding selenium. 


26 


No. 607,003. Composition of Matter For Manu¬ 
facturing Glass. Van Fleet, July 5, 1898. 

The object of my invention is to produce for use 
in the arts a material suitable for many or all of the 
uses to which glass is applied and for uses to which 
ordinary glass cannot be applied because of brittleness, 
said material being superior to common glass in its 
freedom from liability to fracture. 

My invention also has for its object to produce a 
glass especially adapted for use as an insulating ma¬ 
terial for electricity and which, owing to its strength 
and freedom from fracture under sudden and ex¬ 
treme changes of temperature, is particularly applicable 
for employment in connection with engines driven 
by gas, gasolene, or other inflammable matter for 
the generation of electricity, and also in connection 
with other electric appliances where insulators are 
needed of greater strength and higher insulating qua¬ 
lities than those now known. 

My newly invented glass is a vitreous product which 
is characterized as containing a silicate or silicates, 
magnesia, alumina, and water, combined with a suit¬ 
able flux, and which is in structure amorphous, non- 
crystalline, and free from grit. Such a product is 
distinguished from common glass by its superior 
strength, superior electrical insulating qualities, and 
absolute freedom from fracture under sudden and 
very great changes of temperature. The material may 
be heated to any temperature up to fusing and instantly 
cooled, in whole or in part to zero, without fracture. 

The principal ingredients of the composition are 
as follows, compounded in the proportions named: 
silica, 46.19; iron protoxid, 4.70; iron oxid, 2.24; 
magnesia, 12.57; water, 10; alumina, 8; soda and 
potash, not estimated separately; approximately 14.50. 
These ingredients I have found existing in about the 
proportions stated in an ore produced from a mine Io- 


27 


cated near Claremont, in Los Angeles county, Cali¬ 
fornia, which is known in that locality as “green- 
paint ore.” The silica exists in the ore as a silicate 
that is chemically combined with the bases magnesia 
oxid (MgO)', iron oxid (FeO), &c., and does not 
exist as free silica or sand. The ore is distinguished 
as follows: Cleavage, imperfect; fracture, uneven; 
hardness, 2 to 2.5; flexible when wet; brittle when 
dry; color, dark serpentine green with some blue; 
luster, glistening, slightly subvitreous; smooth and 
unctuous to touch; free from grit; specific gravity,2 to 
2.5; structure, smooth non-crystalline. 

To the above-named constituents, whether taken as 
the ore in its natural state or combined artificially, 
after the same have been suitably pulverized, is added 
a flux, preferably composed of litharge in about the 
proportion of two and one-half per cent of the whole 
mixture; commercial borax, two and one-half per 
cent; soda (bicarb.), one and one-half per cent. When 
such flux and the foregoing principal ingredients have 
been suitably mixed and fused, they will form a com¬ 
position that may be defined as a combined hydrous 
silicate of magnesia, alumina, iron, soda and potash, 
having a suitable flux. 

It is to be understood that various other well- 
known fluxes and combinations of fluxes may be used 
instead of the flux which I have named, and that the 
proportions may be varied, and also that the analyses 
of various specimens of ore may vary, the essential 
characteristics of the ore remaining the same. 

The vitreous product varies in color, depending 
upon the character of the fluxes used. I have produced 
specimens much resembling green glass in appear¬ 
ance and other specimens varying in color from white 
to black. The material is smooth and shiny, and 
specimens which I have made will cut ordinary glass, 
and they bear a strong resemblance to obsidian and 
have a conchoidal fracture. 


28 


No. 703,512. Composition for Ruby Glass, Zsig¬ 
mondy, July 1, 1902. 

The requirements of producing a ruby glass adapted 
for pressed and blown glasswares are rather great. 
The glass must be sufficiently cheap, the process of 
coloring must take place regularly and during the 
work, and the color must appear in a sufficiently pure 
shade. The process of coloring as well as the melting 
in must be done without any by-process. 

The present invention relates to a composition for 
ruby glass; and it consists of mixing barytiferous 
glass compositions with certain quantities of gold! 
and then melting this mixture in a glass-furnace. By 
the use of gold and salts of barium, ruby glasses can 
be obtained which becomes colored during the work 
easily and completely in a brilliant shade, and the gold 
is made use of in such a way that its power of color¬ 
ing is utilized in a most efficient measure. These 
glasses of baryta possess, with regard to other glasses, 
the just mentioned superiorities, it being supposed 
that they do not contain certain impurities that in¬ 
fluence the processes of coloring in an unfavorable 
manner, and it is also supposed that unfavorable cir¬ 
cumstances of firing in the furnace on melting in the 
glass do not prevent the after development of the 
color. Further, the proper proportion between silicic 
acid and gold is substantial. The experiments have 
shown that no less than 0.25 parts and no more than 
1.7 parts of gold to ten thousand parts of silicic acid 
(quartzy sand) must be employed. When less than 
0.25 or more than 1.7 parts of gold are employed, 
the glass loses the capability of becoming colored red 
during the work. On employing more than 1.7 parts 
of gold an undesirable result is caused by the precip¬ 
itation of the gold. The most advantageous results 
are obtained with a proportion from 0.6 to 1.4 parts 
of gold to ten thousand parts of silicic acid. 


* 29 


The composition of the glass to which gold is to 
be added can be varied in different ways. For in¬ 
stance, it may be composed of silicic acid, alkalies, and 
baryta only, or other oxids ( or oxygen-bearing com¬ 
pounds, as nitrates and carbonates) of bivalent metals 
may be added to or substituted for part of the alkalies 
or the baryta. A small addition of boric acid is al¬ 
lowed, too. However, an addition of an oxid of anti¬ 
mony or of manganese or of iron or of aluminium 
must be avoided because such an addition in some cases 
prevents the development of the color. The same dis¬ 
advantageous effect is produced by the addition of a 
noticeable quantity of lime. 

Good results have been obtained with glass composi¬ 
tions containing, as metallic oxids, soda and baryta 
only. The baryta may be introduced as oxid of 
barium, hydrate of barium, carbonate of barium, &c. 
However, the nitrate is to be preferred to the other 
compounds. 

As an example of the proportions of mixture with 
which by the addition of gold a pure ruby glass can be 
produced the following may be stated: 1.66, chemical 
equivalents SiO' 2 ; 0.288, chemical equivalents, Na 2 0; 
0.276, chemical equivalents, BaO; or 1.66, chemical 
equivalents, SiO' 2 ; 0.41, chemical equivalents, Na 2 0; 
0.085, chemical equivalents, BaO. 

Also mixtures lying between the above-stated pro¬ 
portions allow the production of a good ruby glass. 
With all these mixtures it is most advantageous to use 
from 0.9 to 0.75 parts of gold to ten thousand parts of 
silicic acid. The gold may be added to the other 
components in one of the usual forms, as a finely-di¬ 
vided metal or as a metallic compound—for instance, 
as chlorid—in a solution sufficiently diluted by water. 

In order to produce according to the present inven¬ 
tion blown articles, it will be preferable at first to cool 
down the glass—for instance, by blowing it into ai 


30 


small mold or by cooling it with water and exposing it 
to the cold air. Then it should be rewarmed and 
blown in a proper mold. 

The described colored glass may also serve for the 
production of molded glasswares. 

I claim: 

1. A composition for ruby glass consisting of a 
barytiferous glass composition to which from 0.25 to 
1.7 parts of gold are added for every ten thousand 
parts of quartzy sand, substantially as described. 

2. A composition for ruby glass consisting of a 
barytiferous glass composition which contains as sub¬ 
stantial metallic oxids soda and baryta and to which 
from 0.25 to 1.7 parts of gold are added for every ten] 
thousand parts of quartzy sand, substantially as de¬ 
scribed. 


No. 777,334. Process of Making Translucent Opal 
Glass, Kempner, Dec. 20, 1904. 

In my process I make the opal glass of sand, soda, 
feldspar poor of lime, and sodium silico fluorid. 

In the process known till now the opal glass was 
made by adding alkaline silicofluorid to the usual 
glass-frit (alkaline lime silicate) ; but this addition 
causes difficulties, having a detrimental influence on 
the opalescence and the fusibility of the glass-frit. 
If no lime is added, then a suitable quantity of alumina 
must be introduced into the glass-frit, as is already 
well known in the manufacture of opal glass through 
the use of cryolite (an element containing fluorin). 

For the purpose of making in an economical way an 
opal-glass frit according to my invention the same is 
composed of sand, soda, feldspar poor of lime, and 
sodium silicofluorid, the two later constituents in the 
proportion of two* to one; but the feldspar of the mix¬ 
ture may amount to three-fourths and the sodium sili¬ 
cofluorid may sink to one-fourth. A suitable composi- 



31 


tion of a glass-frit is one hundred parts of a mixture 
of feldspar and sodium silicofluorid, one hundred and 
sixty to one hundred and eighty parts of silicic acid, 
and thirty-seven and one-half tO' fifty parts of soda. 
The choice in the sand and soda addition is to allow 
for the difference of temperature occurring at times in 
the oven. 

The glass-frit mixture is suitable for a feldspar of 
the following composition; silicic acid, 68.15 per cent; 
alumina, 18.58 per cent; potash, 8.90 per cent; soda, 
3.45 per cent; lime, 0.77 per cent; magnesia, 0.11 per 
cent; water, 0.04 per cent. The use of alumina in 
combination with sodium silicofluorid in manufactur¬ 
ing opal glass is already known; but such a glass-frit 
was never entirely free of lime. 

Having now described the nature of my invention, 
what I claim is— 

1. In a process of making opal glass the use of a 
glass-frit composed of sand, soda, feldspar poor of 
lime and sodium silicofluorid the latter in the propor¬ 
tions of two 1 to one, as and for the purpose specified. 

2. In a process of making opal glass the use of a 
glass-frit composed of one hundred parts of feldspar 
and sodium silicofluorid, one hundred and sixty to one 
hundred and eighty parts of silicic acid and thirty- 
seven and one-half to fifty parts of soda, as and for 
the purpose specified. 

No. 845,552. Manufacture of Glass Articles. Jon- 
kergouw, Feb. 26, 1907. 

The manufacture of glass articles has been effected 
hitherto by melting at a high temperature the raw 
material used and subsequently molding or blowing it 
while hot, so as to give the molten matter the desired 
shape. 

This invention relates to process in which the mold¬ 
ing takes place while the material is cold. 



32 


Broadly stated, the invention consists in preparing 
a mixture of materials which is capable of being con¬ 
verted into glass by the application of heat, molding 
these substances, thoroughly mixed, when cold, and 
then submitting them to the action of heat while still 
in the mold. 

The substances used are as follows : Fontainebleau 
sand, carbonate of soda, borax, chalk and minium. 
Fontainebleau sand may be replaced by any other suit¬ 
able sand or by quartz reduced to powder. Carbonate 
of soda may be replaced by carbonate of potash to 
which may be added a small quantity of nitrate of 
potash. The proportions in which these substances 
are mixed together may vary, as will be readily under¬ 
stood, in accordance with the transparency of the 
product to be obtained. By way of example, the fol¬ 
lowing proportions could be used: Fontainebleau sand, 
608; minimum, 300; carbonate of soda, 50; borax, 12, 
chalk, 30 ; total, 1,000. To the mixture thus consti¬ 
tuted may be added, further, one thousand parts of 
Fontainebleau or other suitable sand. 

Compositions may be employed in which the propor¬ 
tion of Fontainebleau sand is as low as three hundred 
parts in one thousand, and the mixture may be em¬ 
ployed without further addition of Fontainebleau 
sand. 

The above are intended as limit figures. Any pro¬ 
portions comprised within these limits may be usefully 
employed. 

The different substances are thoroughly mixed to¬ 
gether in the shape of powder, and coloring-matters 
may be added—such, for instance, as oxid of cobalt 
for obtaining blue color, oxid of gold for obtaining 
red color, oxid of copper for obtaining green 
color, etc. The mixture is then placed in a suit¬ 
able furnace and for about two hours exposed to a 1 
temperature of 1,500° to 2,000°. If the frit is not 
very fusible, it is simply placed on the hearth of the 


33 


furnace. If, on the contrary, it is very fusible, it can 
be placed in a vessel, so as to prevent the frit from 
flowing. When the frit is sufficiently burned, it has 
the form of paste and is cast into water. It remains 
there in the state of paste and can be kept for! any 
length of time. It is in this form that it is subse¬ 
quently used, as will be seen later on. If the frit is 
very fusible, it is cast dry. The paste thus obtained 
is subsequently ground very fine. Water can be added 
to facilitate the grinding. It is then screened, the 
grade of the screen or the sieve used depending on 
the fineness of the powder it is desired to' obtain. For 
ordinary paste the screen No. 120 can be used, and 
for very fusible paste screens up to No. 90 could be 
used. The excess of water contained in the paste is 
then removed by drying in the air. In this way by the 
above-described method of preparation a series of 
pastes of different colors is obtained, the color depend¬ 
ing, as already stated, on the metallic oxid added to the 
mixture at the moment of the formation of the frit. 
It will be readily understood that since these pastes 
have to be molded cold, as already stated, the chief 
drawback to be avoided is the sticking of the paste to 
the mold after the burning. It was therefore neces¬ 
sary to find a mold of special composition preventing 
sticking of the paste to the wall of the mold during the 
burning. Such a mold comprises as its main constitu¬ 
ents a mixture of clay, kaolin, quartz and burnt plas¬ 
ter, the latter product preventing the sticking and the 
other products forming plastic supports. The propor¬ 
tions of the said substances may vary. The follow¬ 
ing proportions give in practice very good results: 
clay, two; kaolin, two; ground quartz, two; plaster, 
four. For preparing molds from this composition the 
substances are mixed together, and owing to their plas¬ 
ticity they can be easily given the desired shape for 
constituting molds. These molds are then burned at a 
temperature of 1,000° to 2,000°. After burning they 


34 


are slowly cooled and then tempered in lime-water. 
The molds are, moreover, always kept in the said lime- 
water, so that they should have a certain moisture 
at the moment of use. 

To make a glass article by means of one of the 
said molds, the mold is taken from the bath of lime- 
water and the bottom of the mold decorated with frits 
of various colors obtained as described, or with or¬ 
dinary enamels or with a mixture of frits and 
enamels. Over the decoration is heaped lightly a 
white paste or paste of one or even of two colors, ac¬ 
cording to circumstances, so as to fill the mold com¬ 
pletely. To- facilitate the placing in the mold of por¬ 
tions of frits of different colors, according to the or¬ 
namentation that the article is intended to possess, 
brass grates could be used, forming compartments in 
which to place the frits of different colors. After the 
frits have been put in place the brass grates are re¬ 
moved before placing the filling-frit. Instead of the 
brass-grating the frits of various colors can be ar¬ 
ranged either by means of a brush or by hand. The 
mold thus containing the raw material is then intro¬ 
duced into the mold with oxidizing or reducing atmo¬ 
sphere and heated, according to the fusibility, from 
750° to 1,000°. The burning operation lasts about 
fwo hours. Then the mold is removed from the fur¬ 
nace and the articles can be removed from the 
mold without difficulty after cooling. In these condi¬ 
tions and according to the nature of the frits used ar¬ 
ticles completely imitating ceramic articles or vitrified 
articles having the absolute transparency of glass are 
obtained. These articles, according to the decoration 
or ornamentation made at the moment of molding, will 
be of one or many colors, with opaque colored parts, 
obtained by means of frits or with transparent colored 
parts, obtained by means of enamels. 

When it is desired to have an article with very fine 
grain, the molding can be effected under pressure. In 


35 


these conditions the desired cohesion is given to the 
frit by quick burning and the said frit compressed 
while hot in a metal mold (brass or cast-iron). In 
these conditions an article is obtained having the same 
appearance as those obtained by the process hereinbe¬ 
fore described, but having a greater density. 

I claim— 

1. In the manufacture of glass articles, the opera¬ 
tion consisting in preparing a glass composition, cal¬ 
cining the same, pulverizing the calcined material, 
placing the pulverized material while cool into a mold, 
then heating the pulverized material in the mold and 
forming the object therein by fusion, and removing 
the object from the mold after cooling. 

2. In the manufacture of glass articles, the opera* 
tion consisting in melting a mixture containing sili- 
cious matter and carbonate, pulverizing the frit thus 
obtained, placing the pulverized material while cool 
into a mold, then heating the pulverized material in 
the mold and forming the object herein by fusion, and 
removing the object from the mold after cooling. 

3. In the manufacture of glass articles, the steps 
which consist in mixing together sand, minium, car¬ 
bonate, borax, and chalk, fusing said mixture, grind¬ 
ing the frit thus obtained, placing the ground material 
while cool in a mold, and then heating the ground 
material within the mold, and forming the article by 
fusion therein. 


No. 851,317. Opaque Glass, Reinmann, April 23, 
1907. 

This invention has reference to the production of a! 
novel opaque glass and the process of making same. 

It is the special object of my invention to produce 
a new opaque glass which is a close imitation of ala¬ 
baster. 



36 


The new product is a white delicately tinted fine 
grained glass resembling alabaster, but, being a glass, 
is not soft as the mineral alabaster and therefore may 
be used for many more purposes particularly exterior 
decorations and such articles which are subject to< at¬ 
mospheric conditions and moisture. Not only the 
pure white variety of alabaster may be imitated, but 
the clouded varieties may be also colored for certain 
purposes. 

The new alabaster glass is particularly adapted for 
making inner and outer globes for arc lights to hide 
the arc and diffuse the light and for making other 1 
bulbs. All kinds of ornaments heretofore made of 
alabaster may be made of the new glass by blowing, 
pressing or casting them. For instance some house¬ 
hold utensils such as finger-bowls, dishes and vases are 
made from the glass and in this instance the composi¬ 
tion may be tinted with traces of cobaltum or copper 
oxids. The first named will produce a bluish tint and 
the second a greenish tint as is well known. 

The opaqueness of the novel glass is imparted there¬ 
to by admixing finely powdered and sifted asbestos, 
and in some instances a certain percentage of talcum. 
The asbestos renders the glass imperfectly transparent 
or translucent and when some talcum is added a more 
dense and non-transparent glass is obtained which is 
rather impervious to light. It is essential for obtain¬ 
ing a perfect product to have a certain composition in 
combination with the asbestos and care must be taken 
that the glass is fused in a closed pot. In an open pot 
the opaque quality of the glass may not result because 
it may be burned out. 

In carrying my invention into practice I substan¬ 
tially proceed as follows: First the various ingredients 
are weighed and mixed. The composition consists 
of pure white sand, soda, asbestos, arsenic, niter, and 
in some instances of talcum. The preferred percent¬ 
ages of the various components are as follows—Pure 


37 


white sand, 100 pounds, carbonate of soda, preferably 
of 90%, 42 pounds, finely powdered and sifted asbes¬ 
tos, 20 pounds, arsenic, 1 pound, pure niter, 4 pounds. 
When these ingredients have been thoroughly mixed 
they are fused in a closed pot in the usual manner. 
The cover which closes the pot in the front may be 
removed from time to time to watch the process of 
melting. When the composition has been completely 
transformed into glass and the desired opaqueness ob¬ 
tained the front cover is removed. Now, the glass is 
worked up into the desired articles. 

For finger-bowls, dishes, vases and the like some 
cobaltum or copper oxid is admixed in the well known 
mariner for the purpose of obtaining the bluish and 
greenish tints above referred to. For producing a 
more dense non-transparent glass up to 20 pounds of 
finely powdered talcum; may be mixed with the per¬ 
centages of ingredients above stated. The composi¬ 
tion is then melted in the closed pot as above described. 

In order to economize and make use of the cullet 
or scrap of the fused alabaster glass remaining from 
previous days the said scrap is admixed to the compo^ 
sition before it is fused. To the quantity of sub¬ 
stances above given such cullet or scrap of alabaster 
glass may be admixed thereto- up to 50 pounds. 

It is obvious that the percentages of the various in¬ 
gredients of which the imitation alabaster or opaque 
glass is composed may be varied within reasonable 
limits without departing from the spirit of the inven¬ 
tion. 

In the described manner I have produced artificial 
alabaster, white or colored, which does not share the 
deficiency of the mineral alabaster, that is, its soft¬ 
ness. On the contrary my novel substitute alabaster is 
hard because it is a glass and therefore may be used 
for a great many more purposes than the mineral ala¬ 
baster and lasts longer. The articles made from the 


38 


artificial alabaster are easily produced by blowing or 
pressing them in the same manner in which glass is 
worked up. 

I claim: 

1. The composition for artificial alabaster an 

opaque glass consisting of pure white sand, soda 
preferably of 90%, finely powdered and sifted asbes¬ 
tos, arsenic and niter substantially in the proportion 
specified. 

2. The composition for artificial alabaster an 

opaque glass consisting of pure white sand, soda; 
preferably of 90%, finely powdered and sifted asbes¬ 
tos, arsenic and niter substantially in the proportion 
specified, and tinting metallic oxids. 

3. The composition for artificial alabaster an 

opaque glass consisting of about 100 pounds of pure 
white sand, 42 pounds of soda preferably of 90%, 
20 pounds of finely powdered and sifted asbestos, and 
4 pounds of niter. 


No. 965,860. Composition of Matter to Be Used in 
the Manufacture of Glass. Bernasconi, Aug. 
2, 1910. 

This invention relates to improvements in imita¬ 
tion leaded glass, and has for its object the produc¬ 
tion of a composition for forming the outlines, which 
when fired will unite with the glass and resemble 
strongly leaded outlining. 

According to this invention, the composition con¬ 
sists of a mixture of china clay, glass flux, and black 
enamel. With this is mixed a little adhesive such as 
gum arable by which it can be caused to adhere to the 
glass. The outlining may be applied to both sides of 
the glass, which is then fired or baked in a kiln, causing 
the composition used for the lines to fuse. When fired 
the lines harden and unite with the glass. 



39 


For the composition of the mixture of which the 
outlining is composed the following proportions have 
been found suitable: 1 part of hard black enamel, 
known to the British glass trade as No. 31 F. 2 parts 
cf china clay No. 100. parts of glass flux known 
to the trade as No. 157 F. The hard black enamel 
above mentioned is composed of silica, potash, borax, 
manganese and black oxid of copper. The china clay 
is the best white china clay used for china. The glass 
flux is a compound of silica, borax, potash and lead. 
These are thoroughly mixed but the composition will 
not adhere to glass well by itself. To overcome this it 
is mixed with gum arabic and water, a sufficient quan¬ 
tity being used to enable the mixture to adhere to the 
glass in any desired quantity until the glass is “burnt.” 
The gum arabic is only used as an adhesive. 

In carrying out the invention a sheet of glass of 
any suitable kind is placed over a design, and the mix¬ 
ture traced on the glass over the design, in any suit¬ 
able manner. For instance, it may be applied with a 
stick, brush or tube. A sufficient quantity is applied to 
makes the lines stand up, after which the glass is al¬ 
lowed to dry when it can be turned over and the oppo¬ 
site side similarly treated. When thoroughly dry the 
sheet of glass is placed in a cast iron tray and bedded 
down on a bed of plaster of Paris, and is then covered 
by a lid, which leaves a clearance of about four inches. 
Thus a large body of air is interposed between the 
glass and the lid, enabling the firing to be effected 
slowly in the well known manner. 

Preferably the kiln is formed with a view hole so 
that the condition of the glass can be examined from 
time to time. As soon as the lines turn to a dark gray 
color the glass can be removed and it will be found 
that the lines have set hard, having exactly the same 
appearance as the partitions used in leaded glass. 
Conveniently the kiln is so constructed that the tray 
containing the glass, directly it is heated, can be re- 


40 


moved from the back of the kiln and a fresh tray in¬ 
serted and so on continuously. 

In making colored glass the stains are applied to the 
surface of the sheet of glass either before or after the 
outlining has been done and preferably such stains are 
chosen as fuse at the same temperature as the mixture 
used in the; lines, as has hitherto been proposed. If 
desired, however, the proportions of the composition 
of the mixture may be varied to make it fuse at the 
temperature of the stains. The stains can be applied 
to either or both sides of the glass enabling different 
shades to be obtained. 

By the use of the composition above described both 
sides of the glass can be treated without damage to 
the composition before it is burnt, or during the 
process of burning. 

It is found that with this composition the glass ready 
for firing may be embedded down upon plaster of 
Paris or the like without the composition adhering to 
the bed. This is a point of great importance as it en¬ 
ables both sides of the glass to be treated equally well, 
and obviates the necessity for standing the glass on 
edge, which causes it to warp. 

Obviously the rate of firing may vary according to 
circumstances, but preferably it is somewhat slow. 
Again, the composition of the mixture may be varied 
without departing from the invention. The above pro¬ 
portions have been found to effect the purpose satis¬ 
factorily. 

I claim: 

1. The herein described composition of matter com¬ 
prising black enamel (consisting of silica, potash, 
borax, manganese, and black; oxid of copper), china 
clay, and glass flux (consisting of a compound of 
silica, borax, potash and lead), substantially as and for 
the purpose described. 


41 


No. 974,801. Composition of Vitreous Matter. 

Krause, Nov. 8, 1910. 

My invention consists in a new composition of 
matter, of which a conspicuous utility is in the forma¬ 
tion of gas-tight thermally or electrically insulating 
joints between metal and glass or other insulating ma¬ 
terial, or between two metal members. This compo¬ 
sition of matter is adapted to be applied especially to 
metals, such as iron or steel, and will be so applied ini 
a fused or viscous condition under heat. 

The vitreous substance or composition which is to 
serve as a coating or lining for metal, or which is to 
establish efficient hermetical union between two sur¬ 
faces, especially when one at least is a metal surface, 
or which is to unite two metallic members, must be 
susceptible of application in a molten, that is to say, a 
fluid or viscous condition; and it should possess in 
appreciable measure the following properties, to wit: 
First. It should be capable in the fluid or semi-fluid 
condition of dissolving the oxid of a metal to 1 which it 
is applied, so as thus to cleanse the metallic surfaces 
for the purpose of intimate and perfect contact with 
the vitreous composition. Second. It should freely 
wet the surface to' which it is applied. Third. It 
should have a co-efficient of thermal expansion which 
approximates to that of the substance to which it is ap¬ 
plied, in order that, on cooling or when in use the 
united members are subjected to fluctuations of tem¬ 
perature, the vitreous composition may preserve its 
own- integrity and the intimacy of union with the 
member to which it is applied. Fourth. It should be 
mechanically strong, tough and preferably adhesive in 
respect to the materials to which it is applied. Fifth. 
It should fuse at moderate temperatures, not only for 
the sake of ready application but also so as to reduce 
as far as possible in the process of application that 
temperature interval during which strains are likely to 
be established. Sixth. In case the composition is to be 


42 


used to join together two members which have decid¬ 
edly different thermal co-efficient of expansion, as a 
rule this composition to act as an efficient intermediary 
between such members should have a thermal co-effi¬ 
cient of expansion intermediate between the co-effi¬ 
cients of the members joined. 

A composition of matter which constitutes a good 
example of my invention and which possesses the 
above recited properties in an unique degree, is con¬ 
stituted as follows: soda glass, 45%, borax, 45%, 
ferric oxid, 10%. These ingredients are fused to- 
gether so as to form a homogeneous composition. The 
borax furnishes mechanical strength to the composi¬ 
tion, renders it readily fusible at moderate tempera¬ 
tures, and contributes in a marked degree to the ca¬ 
pacity of the composition to cleanse and wet a metal¬ 
lic surface when Applied thereto in a fused condition. 
The ferric oxid contributes also to the toughness and 
ready fusibility of the composition, and renders it 
strongly adhesive to iron and kindred metals. Soda 
glass, as is well known, is composed chiefly of sodium 
and calcium silicate. Presumably the former ingre¬ 
dient is the more essential for the purposes herein¬ 
above indicated, and therefore the calcium silicate 
might well be replaced by some other silicate capable, 
of forming a glass with the sodium silicate without 
seriously modifying the properties of the composition 
in respect to the peculiar utilities contemplated for it. 

Iron belongs to a group of closely kindred elements 
ordinarily known as the iron group, of which the Other 
metals are cobalt, nickel, chromium and manganese. 
The elements of this group manifest striking simi¬ 
larity in physical and chemical properties, both in 
their elementary state and in their compounds ; they 
are adjacent to each other in the elementary series and 
have atomic weights lying in the narrow range be¬ 
tween 52 and 59. A significant index of the close kin¬ 
ship between these metallic elements, is that they are 


43 


notably magnetic in character, exceeding all other ele¬ 
ments in this respect. It is well known that members 
of the iron group on account of their similarity may 
replace one another, not only in many chemical 
processes, but also in compositions of matter, such as 
steel, without radically altering the character of the 
process or the qualities of the material. Thus, as 
might be expected, salts or the oxids of the other 
members of this closely related group will when em¬ 
ployed in the above-described vitreous composition in¬ 
stead of ferric oxid lend to the composition properties 
similar to those conferred by ferric oxid. 

By reason of its properties above alluded to, this 
vitreous fusible homogeneous composition is adapted 
for many useful purposes. By its aid a stout iron) 
wire may be effectively sealed through a glass tube or 
bulb, a result never before accomplished so far as I am 
informed. 

The proportions of the ingredients of this new 
composition of matter can, of course, be varied from 
the precise relative quantities above specified, and 
should be varied to suit the exigencies of different 
though related uses. For instance, if the vitreous 
compound is to be employed simply as a lining or 
coating for an iron or steel body, the formula given) 
above is, I believe, to be preferred, whereas if the com¬ 
position is to be used to* join an iron or steel member 
to a member composed of ordinary glass, an effective 
composition may contain 65%. of soda glass, 22%' of 
borax and 13% of ferric oxide. Obviously in making 
such a composition of matter, a mixture of ferric 
borate and sodium oxid will produce as a result a< 
homogeneous composition the same as with ferric oxid 
and sodium borate. Such reciprocal inversion of the 
ingredient compounds are indifferent so far as con¬ 
cerns the resultant composition. 


44 


I am aware that mixtures of soda glass and borax 
have been used for glazing iron; but these composi¬ 
tions lack both the strength and adhesiveness possessed 
by my new composition of matter, which is character¬ 
ized by an ingredient salt of a metal of the iron group. 
I am also aware that some glasses or enamels have 
been made which contain small amounts of iron, cobalt 
or manganese, either as an impurity or as coloring 
matter; but in no> case so far as I know have the pro¬ 
portions of such ingredients been sufficient appreciably 
to affect the mechanical properties of the glass or 
enamel, nor have they ever been capable, so far as I 
have known,- of exercising the functional capacities 
which my new composition of matter possesses and 
which may be exploited for the purposes above sug¬ 
gested. 

I claim: 

1. A vitreous homogeneous composition composed 
chiefly of sodium boro-silicate and containing further 
the oxid of a metal of the iron group in proportions 
sufficient to> manifest in the composition when fused a 
superficial intimacy with iron or kindred metal. 

2. A vitreous homogeneous composition composed 
chiefly of sodium boro-silicate and containing further 
the oxid of a metal having an atomic weight between 
52 and 59 in proportions sufficient to manifest in the 
composition when fused a superficial intimacy with 
iron or kindred metal. 

3. The composition of soda glass, borax and ferric 
oxid, the last in proportions sufficient to manifest in 
the composition when fused a superficial intimacy with 
iron or kindred metal. 


45 


No. 990,606. Material for Use in the Manufacture 
of Glass, Sullivan, Apr. 25, 1911. 

In the present practice of the manufacture of lead 
glass, the lead is uniformly introduced into the glass 
as lead oxid—either litharge or minium. These are 
expensive materials and difficult to handle without the 
formation of dust and consequent injury to the health 
of the workmen. Some other lead salts have been 
proposed as substitutes for these oxids, such as lead 
sulfate, white lead (lead carbonate), and even lead 
sulfid in connection with sodium sulfate to decompose 
it. None of these substances, however, have been 
practically successful, in so far as I am aware. 

In an application for Letters Patent of the United 
States, of even date herewith, I have described a 
method of incorporating lead into glass in the manu¬ 
facture of lead glass, by using as the direct source of 
the lead, the cheap natural lead sulfid or galena (PbS), 
the most common ore of lead. In carrying out said 
method, the native lead sulfid ore (galena) is first puri¬ 
fied by washing, jigging or other mechanical or chemi¬ 
cal operations, so as to remove from it, in particular, 
any iron minerals associated with it. The purified 
lead sulfide is then mixed, in proper proportions, with 
a difficultly fusible material (for instance a substance 
containing combined or .uncombined silica, such as 
pure sand, or feldspar) of such quality as is suitable 
for glass making. A mixture of the lead sulfid and 
silica (or of the lead sulfid and feldspar), both of 
the required purity for a lead glass charge (excepting 
the sulfur present), is then roasted in any suitable 
form of roasting furnace, at the speed and tempera¬ 
ture best adapted for removing the sulfur most com¬ 
pletely from the roasted material. I have found, for 
instance, that by hand roasting a mixture of three 
parts by weight of pure sand to one part by weight of 
galena in a reverberatory furnace, at a temperature 


46 


rising to between 900 and 1,000 degrees centigrade, 
and allowing the roasting material to remain about 
twenty-four hours in the furnace, with stirring at in¬ 
tervals of one hour, the sulfur remaining has been re¬ 
duced to 0.05 per cent, furnishing a practically pure 
lead product, pure enough to satisfy the very exacting 
requirements of the lead glass maker. The lead-bear¬ 
ing substance, which I thus produce is of a granular, 
non-dusty and sintered form. The small grains ap¬ 
pear to be almost entirely of quartz, with a more or less 
irregularly distributed “pebble-dash” surface of lead 
silicate. Some of the grains carry more of silicate 
than others and the silicate shades into the quartz 
rather gradually, showing all graduations of concen¬ 
tration. At the outer surface, the silicate is apparently 
a pure component judging from its refractive index, 
and the roasted product as a whole appears clean, and 
sufficiently uniform for the purposes intended. 

The lead-bearing substance, produced in accordance 
with the invention, is mixed with any other material 
appropriate to lead glass manufacture and the mixture 
is then fused down to lead glass. I have found that 
a suitable mixture for the purpose may be compounded 
of say the sintered lead product 40 pounds, pearlash 
5 1/2 pounds, soda 4 1/2 pounds and niter 1 pound. 

In compounding and thereafter handling, storing 
or transporting from one part of the works to another 
a batch made with lead silicate, the mixture is found 
to take on and maintain greater uniformity of dis¬ 
tribution of the ingredients throughout the mass than 
when litharge is employed; for the reason, that the 
specific gravity of the lead silicate more nearly cor¬ 
responds to that of the remaining constituents. 

A further advantage to be gained by the use of lead 
silicate in the manufacture of lead glass is that it is free 
from metallic lead, which is present up to one-half of 
one per cent and more even in the best commercial 
litharge, and also to some extent in minium. This 


47 


metallic lead tends to give the glass a darker color, and, 
furthermore, it tends to shorten the life of the glass¬ 
melting pot by eating through the pot wall. 

In manufacturing lead glass containing lime, the 
lime (used as lime, limestone or gypsum) may be 
mixed with the silica and lead sulfid and thus partici¬ 
pate in the roasting operation. Or the lime, limestone 
or gypsum alone may be mixed with the lead sulfid 
and roasted therewith, the silica being introduced 
later in the glass-fusion operation; or the lime, lime¬ 
stone or gypsum may be excluded from the roasting 
operation and used only in the final fusion of glass. 
Such variations fall within the generic principle of my 
process, which is essentially to roast the lead sulfid 
thoroughly mixed with a difficultly fusible substance, 
under test conditions as to purity of the roasted prod¬ 
uct, and then to use this roasted product in glass mak¬ 
ing. 

The lead-containing material or product itself re¬ 
sulting from the practice of the process, and herein¬ 
after claimed, possesses great advantages as a means 
of introducing lead into glass. Its powder is practical¬ 
ly without deleterious effect upon the workmen. The 
product dissolves in glass without any chemical decom¬ 
position, such as necessarily accompanies the use of 
lead sulfate, lead carbonate, or lead sulfid and sodium 
sulfate. Moreover, I have found that my lead-con¬ 
taining material dissolves quickly and uniformly to a 
more homogenous lead glass than can be obtained, so 
far as I am aware, by the use of any of the lead salts 
or compounds before proposed for use in glass making. 

Having thus described my invention, what I claim 
is: 

1. As a new material for use in glass making, the 
granular, sintered product obtained by dead roasting, 
to a percentage of not more than about .05 per cent 
of sulfur, a mixture of galena and a substance diffi- 


48 


cultly-fusible at the roasting temperature but suitable 
to the composition of lead glass; substantially as de¬ 
scribed. 

2. As a new material for use in glass making, a 
granular substance consisting of fused or sintered lead 
silicate associated with silica and practically devoid of 
sulfur; substantially as described. 

3. As a new material for use in glass making, a 
granular substance consisting of fused or sintered 
lead silicate associated with silica and a calcium com¬ 
pound and practically devoid of sulfur; substantially 
as described. 


No. 590,607. Manufacture of Glass. Sullivan, Apr. 
25, 1911. 

As is commonly known, lead glass is glass contain¬ 
ing up to fifty per cent of lead oxid combined with 
silica (Si0 2 ) and alkalis, such as potassa (K 2 0), 
and is at present made by melting together lead oxid 
(either in the form of litharge, (PbO) ; or minium, 
(Pb 3 0 4 ) with a pure sand and potash. The oxids of 
lead used for this purpose must be of a special purity, 
being made from special brands of best refined lead, 
and they command a high price. The manufacture of 
these oxids is a tedious and costly operation, deleteri¬ 
ous to the health of the workmen. The handling and 
mixing of the lead oxids with the glass forming the 
charge is also accompanied by the escape of lead oxid 
dust into the air, so that poisoning of the workmen 
is not infrequent. Furthermore, the lead oxids do not 
dissolve rapidly and uniformly in the glass mixture 
and it requires the highest skill of the melter to pro¬ 
duce glass of fairly homogeneous composition and 
density. 

The object of the present invention is to incorporate 
lead into glass in the manufacture of lead glass, by 
using as the direct source of the lead, the cheap natural 



49 


lead sulfid or galena (PbS), the most common ore of 
lead. As at present practiced, this ore is first reduced 
by a complicated set of metallurgical reactions to crude 
metallic lead; the latter is then refined either by fire 
processes or by electrical refining; the refined lead of 
high purity is then oxidized in special furnaces to lead 
oxid; and finally, the latter is mixed with glass form¬ 
ing materials and melted together therewith to form 
lead glass as hereinbefore indicated. 

My invention consists in first purifying, if necessary, 
the native lead sulfid ore (galena) by washing, jig¬ 
ging, or other mechanical or chemical operations, so as 
to remove from it, in particular, any iron minerals as¬ 
sociated with it. This operation is, in general, cheap 
and easy to perform and involves no operation not 
commonly known and practiced in the purification and 
concentration of metallic minerals. The purified lead 
sulfid is then mixed, in proper proportions with silica 
’of such quality as is suitable for glass making, or with 
any other suitable difficultly fusible substance, such as 
feldspar. This mixture of lead sulfid and silica (or 
of lead sulfid and feldspar), both of the required 
purity for a lead glass charge (excepting the sulfur 
present), is then roasted in any suitable form of 
roasting furnace, at the speed and temperature best 
adapted for removing the sulfur most completely from 
the roasted material. I have found, for instance, that 
by hand roasting a mixture of three parts by weight 
of sand to one part by weight of galena in a rever¬ 
beratory furnace, at a temperature rising to between 
900 degrees and 1,000 degrees centigrade, and allow¬ 
ing the roasting material to remain about twenty- 
four hours in the furnace, with stirring at intervals of 
one hour, the sulfur remaining has been reduced to 
0.05 per cent, furnishing a practically pure lead prod¬ 
uct, pure enough to satisfy the very exacting require¬ 
ments of the lead glass maker. 


50 


I believe that the strict conditions as to purity of the 
materials, and the high elimination of sulfur which 
my experiments have shown possible, are outside of 
any recorded facts or experience in the metallurgical 
roasting of galena ore, and that I am the first to 
demonstrate that a lead-bearing material, practically 
free from sulfur and sufficiently pure for glass making 
purposes, can be practically produced in the manner 
described. 

The lead-bearing substance, which I thus produce, 
is of a granular, non-dusty and sintered form. The 
small grains appear to be almost entirely of quartz 
with a more or less irregular distributed “pebble-dash” 
surface of lead silicate. Some of the grains carry 
more of silicate than others and the silicate shade into 
the quartz rather gradually, showing all graduations 
of concentration. At the outer surface the silicate is 
apparently a pure component, judging from its refrac¬ 
tive index, and the roasted product as a whole appears 
clean, and sufficiently uniform for the purposes in¬ 
tended. 

In compounding, and thereafter handling, storing, 
or transporting from one part of the works to another 
a batch made with lead silicate, the mixture is found 
to take on and maintain greater uniformity of dis¬ 
tribution of the ingredients throughout the mass than 
when litharge is employed; for the reason, that the 
specific gravity of the lead silicate more nearly cor¬ 
responds to that of the remaining constituents. 

A further advantage to be gained by the use of lead 
silicate in the manufacture of lead glass is that it is 
free from metallic lead which is present up to one 7 
half of one per cent, and more even in the best com¬ 
mercial litharge, and also to some extent in minium. 
This metallic lead tends to give the glass a darker 
color, and, furthermore, it tends to shorten the life of 
the glass-melting pot by eating through the pot wall. 


51 


Throughout the entire operation, there is no grind¬ 
ing, mixing or handling of litharge or minium, thus 
avoiding lead oxid dust from those sources and its 
poisonous effects on the workmen. There are, more¬ 
over, only two operations necessary in passing from 
the purified ore to the glass. I believe, moreover, 
that the glass produced is more homogeneous than 
if made by attempting to dissolve free lead oxid in 
glass. 

In manufacturing lead glass containing lime, the 
lime (used as fime, limestone, or gypsum) may be 
mixed with the silica and lead sulfid and thus partici¬ 
pate in the roasting operation; or the lime, limestone 
or gypsum alone may be mixed with the l ead s ulfid 
and roasted therewith, the silica being introduced later 
in the glass fusion operation; or the lime, limestone 
or gypsum may be excluded from the roasting opera¬ 
tion and used only in the final fusion to glass. Such 
variations fall within the generic principle of the proc¬ 
ess devised by me, which is essentially to roast the lead 
sulfid, thoroughly mixed with a difficultly fusible sub¬ 
stance, under test conditions as to purity of the roast¬ 
ed product, and then to use this roasted product in 
glass making. 

Having thus described my invention, what I claim 
is : 

1. The method of manufacturing glass, consisting in 
roasting a mixture of lead sulfid and a difficultly fusibie 
substance appropriate to the manufacture of lead glass, 
adding to the product of the roasting operation the 
other ingredients desirable in such manufacture, and 
fusing the final mixture to a glass; substantially as de¬ 
scribed. 

2. The method of manufacturing glass, consisting 
in roasting a mixture of lead sulfid and silica, adding 
to the product of the roasting operation the other in- 


52 


gredients desirable in the manufacture of lead glass, 
and fusing the final mixture to a glass; substantially 
as described. 

3. The method of manufacturing glass, consisting 
in roasting a mixture of lead sulfid, a silicious sub¬ 
stance and a calcium compound (such as lime, lime¬ 
stone, or gypsum), adding to the product of the roast¬ 
ing operation the other ingredients desirable in the 
manufacture of lead glass, and fusing the final mix¬ 
ture to a glass; substantially as described. 


No. 1,086,113. Vitreous Substance. Wolf, Burck- 
hardt & Borchers (Assigned to Zirkonglass 
Gesellschaft), Feb. 3, 1914. 

This invention relates to the production of a new 
or improved vitreous substance of the nature of quartz 
glass but of greater strength and less liable to devitri¬ 
fication and deformation when subjected to heat. 

Quartz glass, as is well known, is obtained by melt¬ 
ing pure natural quartz or silica free from water, 
which gives a vitreous substance having all the out¬ 
ward properties of glass but being different therefrom 
in its chemical composition, being a substance of pure 
acid character possessing great durability against 
chemical and thermal influences. Quartz glass, how¬ 
ever, when subjected to high temperatures, tends to 
devitrify, that is to say, it transforms from the 
amorphous state into a crystalline state, in which con¬ 
dition it considerably diminishes in strength and may 
be crushed between the fingers. Moreover, when 
quartz is gradually heated to fusing point, it is found 
that it begins to soften at a temperature of about 
1700° centigrade, which is somewhat below that of its 
fusing point. As soon as the softening point is reached, 
the quartz glass rapidly deforms, that is to say, rapidly 
loses its shape, and for these reasons quartz glass has 
been found deficient for many practical purposes. 




The object of the present invention is therefore to 
produce a vitreous substance which, while possessing 
all the good qualities of quartz glass, will be of greater 
strength, being less liable to devitrification and defor¬ 
mation, thus enabling articles to be manufactured 
therefrom which shall be excellently durable against 
thermal influences. 

According to the present invention, small quantities 
of one or more of the acidic oxids of the fourth group 
of the periodic system are incorporated with the 
quartz glass during its manufacture. These acidic 
oxids are very durable against chemical and thermal 
influences, but, of these oxids, the titanic and zirconium 
oxids are most suitable because of their high melting 
point and because their resistance to acids closely ap¬ 
proximates that of silica. The oxids dissolve in the 
molten silica or form silicates therewith which dis¬ 
solve in the excess molten silica and, owing to their 
high melting points, the fusing point of the mixture 
will vary but little and may even exceed that of pure 
quartz glass. It has been found preferable not to add 
more than 5 per cent of these oxids and that when 
the oxids are added to the silica in from fractions of 
one per cent to about 5 per cent, the liability of the 
product to devitrify is considerably less than that of 
pure quartz glass while, at the same time, the softening 
point is slightly higher than that of quartz glass and 
that when this softening point is reached, the product 
does not deform as rapidly as does pure quartz glass. 
The product is also capable of withstanding greater 
breaking strains and is also of greater durability 
against chemical influences than pure quartz glass. 

It will be understood that either titanic oxid or 
zirconium oxid or both may be mixed with the silica 
prior to fusion. 

The mixture of the silica and oxids may be fused 
in an electric furnace or by means of an oxy-hydrogen 


54 


or oxy-coal gas flame or the like. The vitreous sub¬ 
stance thus obtained may be worked and treated in the 
ordinary manner. 

We claim: 

1. As a new composition of matter, a vitreous sub¬ 
stance of the nature of quartz glass and derived from 
silica and a small quantity, not exceeding 5 per cent 
of an acidic oxid of the fourth group of the periodic 
system, characterized by its durability against devitri¬ 
fication and deformation and its capability of with¬ 
standing breaking strains and chemical influences. 

2. As a new composition of matter, a vitreous sub-4 
stance of the nature of quartz glass and derived from 
silica and a small quantity, not exceeding 5 per cent, 
of a plurality of acidic oxids of the fourth group of 
the periodic system, characterized by its durability 
against devitrification and deformation and its cap¬ 
ability of withstanding breaking strains and chemical 
influences. 


No. 1,097,600. Method and Batch or Mixture for 
Making Illuminating Glass. Macbeth (Assigned 
to Macbeth-Evans Glass Co.). 

The invention relates to a method and batch or mix¬ 
ture for making glass for illuminating purposes such 
as in electric and other shades and globes. It has for 
its primary objects, the provision of a process and 
batch which will produce a snow white glass which is 
not clear but which is translucent to a high degree and 
will transmit light without the reddish or yellow color 
known as fire, the glass in these respects distinguish¬ 
ing from the well known opal glasses which are either 
substantially opaque (and known as milk glass) or 
are to some degree translucent, in which case the color¬ 
ing above referred to as fire is always noticed when 
light is observed through the glass; the provision of a 
process and batch which will produce a glass which 
transmits light better than the opal glasses and which 



55 


is subject to a minimum amount of breakage upon the 
application of heat, and the provision of a batch and 
process which will produce a glass having a white 
luminous appearance when transmitting light, with 
such light diffused in a pleasing manner restful to the 
eyes, and with a minimum loss of illuminating power. 

In carrying out my invention I first take a batch or 
mixture somewhat similar to a batch or mixture used 
in the manufacture of colorless clear glass, the pre¬ 
ferred ingredients whereof will be hereinafter more 
particularly pointed out, and to such basic batch or 
mixture I add substances, one of which is preferably 
oxid of aluminum and the other a fluorid, preferably 
fluorspar, although some other fluorid might be used. 
The use of the oxid of aluminum with this fluorid ap¬ 
parently produces throughout the glass minute specks, 
the larger of which are ordinarily visible to the naked 
eye, and which have the effect of diffusing or scatter¬ 
ing the light and giving the glass its white luminous 
appearance. The specks in the finished ware are 
elongated in shape, and I believe them to be bubbles of 
silicon fluorid e^s h~ld H suspension in the material 
and elongated during pressing or blowing the glass in¬ 
to molds. 

In manipulating the glass batch, the duration of op¬ 
eration and the degree of heat must be regulated so as 
not to entirely obliterate the so-called specks or bubbles, 
which obliteration appears to result when the heating 
is too intense or is carried on for too long a period. I 
therefore stop the heating operation at a time short 
of the production of complete transparency and the 
obliteration of the specks or bubbles from the glass, 
the glass tending to return to its colorless crystal stage 
if the operation is continued too long. In carrying 
out the operation I have found that good results are 
obtained in a furnace working at a temperature of ap¬ 
proximately 2,700 degrees F., although this may be 
varied, and changes in temperature (as between 2,500 


56 


degrees and 3,000 degrees F.) may be compensated 
for, in a measure at least, by variations in the mixture 
or the length of time of the operation, which latter 
in many cases I have found to be less than twenty- 
four hours. 

The specific combination of ingredients in the foun¬ 
dation or basic mixture or batch which I have found 
to give the best results is as follows: 


Sand 

100 lbs. 

Lead Oxid 

15^ lbs. 

Soda 

21% lbs. 

Niter 

5 y 2 lbs. 

Salt 

5*4 lbs. 

Borax 

1% to2>4 lbs. 


To the foregoing batch are added 18.12 pounds of 
hydrate of aluminum (A1 2 H G 0 6 ) containing about 
11.84 pounds of oxid of alumina (A1 2 0 3 ) and six 
pounds of fluorspar (CaF 2 ). The materials are mixed 
together and fused as heretofore indicated. 

The proportions of the oxid of alumina and the 
fluorid are not absolutely fixed, but may vary some¬ 
what. The limit in the ratio of the fluorid to> the oxid 
of alumina is reached when the resultant glass becomes 
an opal glass instead of a translucent glass without the 
fire characteristics of the opal glass. The relative pro¬ 
portions will also vary somewhat, depending upon the 
variations in the basic or foundation glass. 

The glass produced by the present process is dis¬ 
tinguished from other glasses containing fluorin, by 
the fact that the glass of the present process is trans¬ 
lucent and yet without the characteristic known as fire 
of opal, whereas the fluorid glasses as heretofore pro¬ 
duced were all properly definable as milk or opal 
glasses, being either white and opaque, or else par¬ 
tially opaque and showing with transmitted light a 
reddish or yellow color knowh to the trade as fire and 
bearing a resemblance to the color in natural opals. 



57 


What I claim is: 

1. The herein described method of manufacturing 
illuminating glass, which consists* in fusing together 
a foundation mixture capable of making substantially 
colorless clear glass with an aluminum oxid compound, 
and a fluorid, the quantity of the aluminum oxid com¬ 
pound by weight being greater than that of the fluorid, 
and the amount of aluminum by weight contained in 
the aluminum oxid compound being greater than that 
of the fluorin contained in the fluorid, and the heat¬ 
ing operation being stopped before the glass returns 
to a clear glass stage and before the specks are elim¬ 
inated. 

2. The herein described method of manufacturing 
illuminating glass, which consists in fusing together a 
foundation mixture capable of making substantially 
colorless clear glass and including a chlorid, with an 
aluminum compound and a fluorin compound, the 
quantity by weight of the aluminum contained in the 
aluminum compound being greater than that of the 
fluorin contained in the fluorin compound, and the 
heating operation being stopped before the glass re¬ 
turns to a clear glass stage and before the specks are 
eliminated. 

3. The herein described mixture for manufacturing 
illuminating glass, which consists in a foundation mix¬ 
ture capable of making substantially colorless clear 
glass, oxid of aluminum and a fluorid, in the following 
quantities by weight—150 parts of the foundation 
mixture, 9 to 15 parts of oxid of aluminum, and 3 to 8 
parts of the fluorid. 


58 


Reissue No. 13,766. Method and Batch or Mixture 
for Making Illuminating Glass, Macbeth (As¬ 
signed to Macbeth Evans Glass Co.), July 7, 
1914. 

The invention relates to a method and batch or mix¬ 
ture for making glass for illuminating purposes such 
as in electric and other shades and globes. It has for 
its primary objects, the provision of a process and 
batch which will produce a snow white glass which is 
not clear but which is translucent to a high degree and 
will transmit light without the reddish or yellow color 
known as fire, the glass in these respects distinguishing 
from the well known opal glasses which are either 
substantially opaque (and known as milk glass) or are 
to some degree translucent, in which case the color¬ 
ing above referred to as fire is always noticed when 
light is observed through the glass; the provision of 
a process and batch which will produce a glass which 
transmits light better than the opal glasses and which 
is subject to a minimum amount of breakage upon the 
application of heat, and the provision of a batch and n 
process which will produce a glass having a white 
luminous appearance when transmitting light, with 
such light diffused in a pleasing manner restful to the 
eyes, and with a minimum loss of illuminating power. 

In carrying out my invention, I first take a batch or 
mixture somewhat similar to a batch or mixture used 
in the manufacture of colorless clear glass, the pre¬ 
ferred ingredients whereof will be hereinafter more 
particularly pointed out, and to such basic batch or 
mixture I add substances, one of which is preferably 
oxid of aluminum and the other a fluorid, preferably 
fluorspar, although some other fluorid might be used. 
The use of the oxid of aluminum with this fluorid ap¬ 
parently produces throughout the glass minute specks, 
the larger of which are ordinarily visible to the naked 
eye, and which have the effect of diffusing or scatter¬ 
ing the light and giving the glass its white luminous 


59 


appearance. The specks in the finished ware are 
elongated in shape, and I believe them to be bubbles of 
silicon fluorid gas held in suspension in the material 
and elongated during pressing or blowing the glass in¬ 
to molds. 

In manipulating the glass batch, the duration of op¬ 
eration and the degree of heat must be regulated so as 
not to entirely obliterate the so-called specks or bubbles, 
which obliteration appears to result when the heat¬ 
ing is too intense or is carried on for too long a pe¬ 
riod. I therefore stop the heating operation at a time 
short of the production of complete transparency and 
the obliteration of the specks or bubbles from the glass, 
the glass tending to return to its colorless crystal stage 
if the operation is continued too long. In carrying out 
the operation I have found that good results are ob¬ 
tained in a furnace working at a temperature of ap¬ 
proximately 2,700 degrees F., although this may be 
varied, and changes in temperature (as between 2,500 
degrees and 3,000 degrees F.) may be compensated 
for, in a measure at least, by variations in the mix¬ 
ture or the length of time of the operation, which lat¬ 
ter in many cases I have found to be less than twenty- 
four hours. 

The specific combination of ingredients in the foun¬ 
dation or basic mixture or batch which I have found 
to give the best results is as follows: 


Sand 

100 lbs. 

Lead oxid 

155/s lbs. 

Soda 

21 % lbs. 

Niter 

5y 2 lbs. 

Salt 

5 y 2 lbs. 

Borax 

ly to 2 y 2 lbs. 


To the foregoing batch are added 18.12 pounds of 
hydrate of aluminum (A1 2 H 6 0 6 ) containing about 
11.84 pounds of oxid' of alumina (A1 2 0 3 ) and six 
pounds of fluorspar (CaF 2 ). The materials are mixed 
together and fused as heretofore indicated. 


00 


The proportions of the oxid of alumina and the 
fluorid are not absolutely fixed, but may vary some¬ 
what. The limit in the ratio of the fluorid to the oxid 
of alumina is reached when the resultant glass becomes 
an opal glass instead of a translucent glass without the 
fire characteristics of the opal glass. The relative pro¬ 
portions will also vary somewhat, depending upon the 
variations in the basis or foundation glass. 

The glass produced by the present process is distin¬ 
guished from other glasses containing fluorin, by the 
fact that the glass of the present process is translucent 
and yet without the characteristic known as fire of 
opal, whereas the fluorid glasses as heretofore pro¬ 
duced were all properly definable as milk or opal 
glasses, being either white and opaque, or else partially 
opaque and showing with transmitted light a reddish 
or yellow color known to the trade as fire and bearing 
a resemblance to the color in natural opals. 

What I claim is: 

1. The herein described method of manufacturing 
illuminating glass, which consists in fusing together a 
foundation mixture capable of making substantially 
colorless clear glass with an aluminum oxid com¬ 
pound, and a fluorid, the quantity of the aluminum 
oxid compound by weight being greater than that of 
the fluorid, and the amount of aluminum by weight 
contained in the aluminum oxid compound being great¬ 
er than that of the fluorin contained in the fluorid, and 
the heating operation being stopped before the glass 
returns to a clear glass stage and before the specks 
are eliminated. 

2. The herein described method of manufacturing 
illuminating glass, which consists in fusing together a 
foundation mixture capable of making substantially 
colorless clear glass and including a chlorid, with an 
aluminum compound and a fluorin compound, the 
quantity by weight of the aluminum contained in the 
aluminum compound being greater than that of the 


61 


fluorin contained in the fluorin compound, and the 
heating operation being stopped before the glass re¬ 
turns to a clear glass stage and before the specks are 
eliminated. 

3. The herein described mixture for manufacturing 
illuminating glass, which consists in a foundation mix¬ 
ture capable of making substantially colorless clear 
glass, oxid of aluminum and a fluorid, in the following 
quantities by weight—150 parts of the foundation 
mixture, 9 to 15 parts of oxid of aluminum, and 3 to 
8 parts of the fluorid. 

4. The herein described mixture for manufacturing 
illuminating glass, which consists in a batch containing 
150 parts by weight of the foundation mixture capable 
of making substantially colorless clear glass, a com¬ 
pound containing aluminum and a compound contain¬ 
ing fluorin, the quantity of the aluminum in the batch 
by weight being from 4 to 8 parts, and the quantity 
of fluorin in the batch by weight ranging from 2 to 4 
parts. 

5. The herein described mixture for manufacturing 
illuminating glass, which consists in a foundation 
mixture capable of making substantially colorless clear 
glass and including a chlorid, an aluminum compound, 
and a fluorin compound, the amount of aluminum by 
weight contained in the aluminum compound being 
greater than that of the fluorin contained in the fluorin 
compound, and the weight of the aluminum and fluorin 
combined being at least 1% of that of the entire 
mixture. v 

6. The herein described mixture for manufacturing 
illuminating glass, which consists in a foundation 
mixture capable of making substantially colorless clear 
glass, an aluminum compound and a fluorin com¬ 
pound, the amount of fluorin by weight contained in 
the fluorin compound being less than 61% of that of 
the aluminum contained in the aluminum compound, 
and the weight of aluminum and fluorin compound 


62 


combined being at least 1% of that of the entire mix¬ 
ture. 

7. The herein described mixture for manufactur¬ 
ing illuminating glass, which consists in a foundation 
mixture capable of making substantially colorless clear 
glass, an aluminum compound and a fluorin compound, 
the amount of aluminum by weight contained in the 
aluminum compound being greater than that of the 
fluorin contained in the fluorin compound, and the 
weight of the aluminum and fluorin combined being at 
least 1% of the entire mixture. 

No. 1,122,065. Artificial-Lighting Means. Brady 
(Assigned to United Gas Improvement Co.), 
Dec. 22, 1914. 

The invention relates to color filters or absorbing 
screens which operate to modify artificial light passing 
through them so as to produce a resultant illumination 
equivalent to daylight. 

The principal object of the present invention is to 
provide an efficient color filter or absorbing screen 
which may be constructed wholly of glass and which 
may therefore assume various forms useful in the 
arts, such as bulbs for incandescent electric lights and 
shades of various kinds. 

An absorbing screen or color filter in order to after' 
an artificial light spectrum to that of daylight must 
absorb excessive radiations. If the relative intensities 
of the different colors of the spectrum are plotted up¬ 
on such a scale that the intensities of daylight and the 
artificial light sources are the same at the blue ex¬ 
tremity of the spectrum, then the transmission of the 
absorbing screen must be as the reciprocal of the ratio 
at each color of the intensity of the artificial light spec¬ 
trum to the daylight spectrum. 

The color filter or absorbing screen is adapted by 
absorption to produce the above described, or perhaps 
more accurately a very close approximation to it. 

In the present invention the color filter or absorb¬ 
ing screen is of signal green and purple color, with or 


63 


without a blue color. There is nothing new about the 
signal green and purple color, but the point of the 
present invention is that the color filter or screen may 
consist of glass containing or embodying these colors 
and since it is of glass, is otherwise proper and effec¬ 
tive for the purpose in hand, it can be used, for exam¬ 
ple, as the globe or bulb of an electric light and in that 
case there is provided a source of artificial illumina¬ 
tion which has the effect of daylight, and such a source 
of artificial daylight illumination is so far as I know at 
present unknown. 

I am, of course, aware of the fact that color screens 
or filters have been made or suggested but I do not 
believe that there ever existed a source of light such 
as an electric lamp in which the globe or bulb operated 
to make the electric lamp produce immediately and di¬ 
rectly the effect of daylight illumination. 

To produce glass of the requisite purple color, use is 
made of nickel which may be introduced as nickel oxid 
or salts and the use of this material for the purpose 
of making artificial daylight glass, I believe to be 
novel. It is well known that signal green glass can be 
produced by the use of copper and blue glass can be 
produced by the use of cobalt. 

By way of further description, and not limitation, 
it may be said that where potash lime glass is used the 
following proportions produce good results: 


Sand 

Potassium carbonate 
Calcium carbonate 
Potassium nitrate 


.208 pounds. 
.091 “ 

.025 “ 

.0167 “ 


To a batch weighing one-third of a pound or 2,333 
grains, four grains of black nickel oxid, Ni 2 0 3 , may be 
added to produce the required kind of purple glass. 
To a similar batch 15 grains of black copper oxid may 
be added to produce the signal green glass of required 
color. When this is done the glasses would be sepa- 


64 


rate and could be intimately mixed. Instead of doing 
this the nickel oxid and the copper oxid in the quantity 
stated may be added to the batch of glass and in that 
case the result is the same and there is but one layer 
of glass. Oxid of cobalt may be added to a proper 
batch of glass, making material to produce blue glass, 
or the oxid of cobalt may be added along with the oxid 
of nickel and oxid of copper. 

In giving proportions of the coloring materials it 
must be borne in mind that the proportions are not 
hard and fast, but are to be changed so as to produce 
the desired result from any artificial light under con¬ 
sideration, having regard to the thickness of the glass. 
This is well understood by those skilled in the art. 

What I claim is: 

1. A color filter or absorbing screen for transform¬ 
ing the light of artificial illuminants to daylight char¬ 
acter comprising a glass composition containing nickel, 
copper and cobalt and being of generally blue color 
when viewed by daylight. 

2. A color filter or absorbing screen for transform¬ 
ing the light of artificial illuminants to daylight char¬ 
acter comprising a potash glass composition contain¬ 
ing nickel, copper and cobalt and being of generally 
blue color when viewed by daylight. 


No. 1,122,066. Artificial Lighting Means. Brady. 

(Assigned to United Gas Improvement Co.). 

Dec. 22, 1914. 

The invention relates to color filters or absorbing 
screens which operate to modify artificial light pass¬ 
ing through them so as to produce a resultant illumina¬ 
tion equivalent to daylight. 

The principal object of the present invention is to 
provide an efficient color filter or absorbing screen 
which may be constructed wholly of glass and which 
may therefore assume various forms useful in the 



65 


arts, such as bulbs for incandescent electric lights and 
shades of various kinds. 

An absorbing screen or color filter in order to alter 
an artificial light spectrum to that of daylight must 
absorb these radiations. If the relative intensities of 
the different colors of the spectrum are plotted upon 
such a scale that the intensities of daylight and the 
artificial light sources are the same at the blue ex¬ 
tremity of the spectrum, then the transmission of the 
absorbing screen must be as the reciprocal of the ratio 
at each color of the intensity of the artificial light spec¬ 
trum to the daylight spectrum. 

The color filter or absorbing screen is adapted by 
absorption to produce the above described result, or 
perhaps more accurately, a very close approximation 
to it. 

In the present invention the color filter or absorb¬ 
ing screen is of purple color and blue color. The 
point of the present invention is that the color filter or 
screen may consist of glass, containing or embodying 
these colors and since it is of glass and is otherwise 
proper and effective for the purpose in hand, it can be 
used, for example, as the globe or bulb of an electric 
light and in that case there is provided a source of 
artificial illumination which has the effect of daylight 
and such a source of artificial daylight illumination is 
so far as I know at present unknown. 

I am, of course, aware of the fact that color screens 
or filters have been made or suggested, but I do not 
believe that there ever existed a source of light such 
as an electric lamp in which the globe or bulb operated 
to make the electric lamp produce immediately and 
directly the effect of daylight illumination. 

To produce glass of the requisite generally blue 
color and absorbing qualities, use is made of nickel 
which may be introduced as nickel oxid or salts, and 
the use of this material for the purpose of making arti¬ 
ficial daylight glass I believe to be novel. It is well 


66 


known that blue glass can be produced by the use of 
cobalt. 

By way of further description, and not limitation, 
it may be said that where potash lime glass is used the 
following proportions produce good results: 


Sand 

Potassium carbonate 
Calcium carbonate 
Potassium nitrate 


.208 pounds. 
.091 “ 

.025 “ 

.0167 “ 


To a batch weighing one-third of a pound or 2,333 
grains, four grains of black nickel oxid, Ni 2 0 3 , may be 
added to produce the required kind of purple glass. To 
a similar batch cobalt oxid may be added to produce 
the blue glass of required color. When this is done 
the glasses can be mixed together. Instead of doing 
this, the nickel oxid and the cobalt oxid may be added 
to the batch of glass. 

In giving proportions of the coloring materials it 
must be borne in mind that the proportions are not 
hard and fast, but are to be changed so as to produce 
the desired result from any artificial light under con¬ 
sideration, having regard to the thickness of the glass. 
This is well understood by those skilled in the art. 

I claim: 

1. A color filter or absorbing screen for transform¬ 
ing the light of artificial illuminants to daylight char¬ 
acter comprising a glass composition containing nickel 
and cobalt and being of generally blue color when 
viewed by daylight. 

2. A color filter or absorbing screen for transform¬ 
ing the light of artificial illuminants to daylight char¬ 
acter comprising a potash glass composition contain¬ 
ing nickel and cobalt and being of generally blue color 
when viewed by daylight.. 


67 


No. 1,130,767. Composition for Making Glass. 
Schott. (Assigned to Schott and Gen.), Mar 9, 
1915. 

By the invention a kind of glass is realized, which 
considerably surpasses in its capacity of resisting 
chemical action the well known kinds of glass of about 
the same cost of production and of the same general 
applicability. In consequence of this property the new 
kind of glass is particularly suitable for chemical ap¬ 
paratus and for gage-glasses. 

In the kind of glass according to the present inven¬ 
tion at least 50 per cent of silicic acid is made use of as 
in well known kinds of glass. Besides the said silicic 
acid the new glass further contains alumina 4 to 15 
per cent, lime 3 to 11 per cent, boracic acid 5 to 15 per 
cent, and alkali 4 to 14 per cent. The percentage of 
alumina and lime together however must amount to 
not less than half and not more than five times the per¬ 
centage of the boracic acid. While no other glass¬ 
forming components are employed for the new kind of * 
glass, of course the addition of a small quantity of one 
or more other substances having some such secondary 
purpose as a coloring of the glass is not excluded. 

Soda is suitable as the alkaline component. Ac¬ 
cording to the experience gained, when working out 
the invention, the new kind of glass displays a par¬ 
ticularly great capacity of resisting chemical action, , 
when in the choice of the amount of soda and of the 
amount of alumina these amounts are kept well within 
the limits given above, i. e., when with a proportion 
of soda of 8 to 12 per cent not less than about 6, but 
also not more than about 12 per cent of alumina are 
taken. 

I claim: 

1. Glass containing at least 50 per cent silicic acid 
and having as its other glass forming components 
alumina 4 to 15 per cent, lime 3 to 11 per cent, boracic 
acid 5 to 15 per cent and alkali 4 to 14 per cent, the 


total percentage of alumina and lime being at least 
half and at most five times that of the boracic acid. 

2. Glass containing at least 50 per cent silicic acid 
and having as its other glass forming components 
alumina 6 to 12 per cent, lime 3 to 11 per cent, boracic 
acid 5 to 15 per cent and soda 8 to 12 per cent, the 
total percentage of alumina and lime being at least half 
and at most five times that of the boracic acid. 


No. 1,136,504. Glass and Art of Making the Same. 

Brookfield, Apr. 20, 1915. 

The object of the present invention is to obtain 
a vitreous product of tough, hard and durable qual¬ 
ity which can be worked like plastic glass into vari¬ 
ous shapes such as insulators. The product obtained 
from this process may be suitably called a glass com¬ 
pound since it takes on the character of glass to a 
large degree and consists in a mixture of glass ma¬ 
terial with an ingredient for giving toughness and 
hardness thereto. This toughening ingredient which 
may be one of the common clays used in porcelain 
making, is added to the glass in suitable proportions 
so as not to destroy the vitreous character of the 
product but on the contrary to remain sufficiently 
plastic after fusion to be molded and pressed in the 
various shapes desired. 

In carrying out my process I first pulverize a quan¬ 
tity of previously formed glass or cullet and thor¬ 
oughly mix with the same a suitable percentage of 
pulverized clay or its equivalent. The cullet may 
be obtained from ordinary scrap glass containing por¬ 
tions of lime or lead glass, but if manufactured par¬ 
ticularly for this process, the lime glass is preferred 
on account of its cheapness. The clays suitable for 
my purpose may be either the primary clays such as 
kaolin, or the secondary clays commonly known as 
pipe or ball clay, although the more infusible clays 
such as the fire clays containing large quantities of 
free silica, quartz, etc, are less preferred. The two 



69 


ingredients of my mixture, namely, the cullet and the 
clay, may be ground to a powder either separately 
and afterward mixed, although I prefer to grind them 
together to obtain a more thorough and intimate mix¬ 
ture. This mixture is then heated to approximately 
2,500° Fahrenheit for fusing the same and render¬ 
ing the mass sufficiently plastic so as to be workable 
into glass articles. The proportion of clay in the mix¬ 
ture may be varied widely, but is preferably kept small 
enough so that the mixture will not be absolutely in¬ 
fusible at the temperature stated. On the other hand 
this proportion of clay may be large enough to cause 
the mass to only partially fuse into a semi-plastic, 
semi-liquid condition which is workable into articles. 

I have found that suitable proportions for the orig¬ 
inal mixture are 30 pounds of day or equivalent, to 
every 100 pounds of cullet. If too large a percentage 
of clay is added to the mixture, the mass upon heat¬ 
ing, will not be sufficiently fused to become homo¬ 
geneous, since portions of the clay collect in irregular 
unfused lumps throughout the mass. If desired, pul¬ 
verized lime CaO may also be added together with 
the clay to the cullet, as an ingredient of the orig¬ 
inal mixture, since it increases the fusibility of the 
clay, and also possesses the same quality as clay in 
rendering the resulting product tough and durable. 

It will thus be seen that by the present process 
a vitreous product of amorphous character is pro¬ 
duced, having all of the advantageous characteristics 
of glass in being plastic and workable, and yet tougher 
andj more durable than ordinary glass products. 

What I claim is: 

1. The process of making a glass compound, which 
is non-crystalline in character, which consists in thor¬ 
oughly mixing pulverized glass or cullet with pulver¬ 
ized clay, the proportion of glass being comparatively 
large, subjecting the same to an approximate heat 
of 2,500° F., cooling and annealing the same. 


70 


2 The process of making a glass compound, which 
is non-crystalline in character, which consists in thor¬ 
oughly mixing pulverized glass or cullet with pul¬ 
verized clay and lime, the proportion of (glass being 
comparatively large, subjecting the same to approxi^ 
mate heat of 2,500° F., cooling and annealing the 
same. 


1,143,732. Glass. Schott (Assigned to Schott & 

Gen.), June 22, 1915. 

Further investigations regarding the glass pro¬ 
tected by Patent No. 1,130,767 have shown, that a 
glass capable of withstanding chemical influences may 
also be obtained, if the lime be wholly or in part 
replaced by magnesia, zinc oxid or baryta, the pro¬ 
portions being so chosen that the place of a part by 
weight of lime is always taken by an equivalent quan¬ 
tity of one of the said substitute substances or of sev¬ 
eral of them. While no other glass-forming compon¬ 
ents are employed for the new kind of glass, of course 
the addition of a small quantity of one or more other 
substances having some such secondary purpose as a 
coloring of the glass is not excluded. 

The following table contains six examples. Ex¬ 
ample I gives the composition of a kind of glass ac¬ 
cording to the above patent, while examples II to 
VI give the composition of new kinds of glass. All 
the examples contain the same percentages respectively 
of alkali, boracic acid and alumina; the 3% of lime 
of example I are replaced in example II by the equiva¬ 
lent quantity of magnesia (2.2%), in example III 
by the equivalent quantity of zinc oxid (4.3%), 
and in example IV by the equivalent quantity of 
baryta (8.2%). In example V 2% of lime are re¬ 
tained, while 1 % of lime is replaced by the equivalent 
quantity of magnesia (0.7%), and in example VI 
the proportion of lime of example I is replaced by 



71 


magnesia and zinc oxide (1.1% and 2.1%). The pro¬ 
portion of silicic acid in examples II to VI is partly 
greater and partly less than in example I. 



I. 

II. 

III. 

IV. 

V. 

VI. 

Alkali 

13 

13 

13 

13 

13 

13 

Boracic acid 

10 

10 

10 

10 

10 

10 

Lime 

3 




2 


Magnesia 


2.2 



0.7 

1.1 

Zinc oxid 



4.3 



2.1 

Baryta 




8.2 



Alumina 

12 

12 

12 

12 

12 

12 

Silicic acid 

62 

62.8 

60.7 

56.8 

62.3 

61.8 


Claim: 

Glass containing at least 50 per cent silicic acid and 
having as its other glass forming components, alu¬ 
mina, 4 to 15 per cent; boracic acid, 5 to 15 per cent; 
alkali, 4 to 14 per cent; magnesia, at most, 7.8 per 
cent; zinc oxid, at most, 15.9 per cent; baryta, at 
most, 30 per cent; and lime, the total percentage 
of lime, magnesia, zinc oxid and baryta being a quan¬ 
tity representing the equivalent of from 3 to 11 per 
cent of lime, the total percentage of alumina, lime 
and that quantity of lime, which would represent 
the equivalent of the percentages of majgnesia, zinc 
oxid and baryta being at least half and at most five 
times that of the boracic acid and the total percentage 
of magnesia, zinc oxid and baryta being greater than 
zero. 


No. 1,143,788. Glass and Batch for Making the 

Same. Schnelbach (Assigned to Macbeth-Evans 
Glass Co.), June 22, 1915. 

My invention relates to a new and useful composi¬ 
tion for the manufacture of translucent and opaque 
glass. 

My invention consists in the composition herein¬ 
after specified for the manufacture of translucent and 
opaque glass. 



72 


In the manufacture of my new and improved glass, 
I use the following mixture or batch of ingredients, 
substantially in the proportions by weight hereinafter 
indicated, to wit: sand, 345.8 pounds; litharge, 56.8 
pounds; soda ash (carbonate of soda), 86.4 pounds; 
cryolite, 20 pounds; aluminum oxid, 60 pounds; niter, 
32 pounds; borax, 8 pounds; plaster of Paris (cal¬ 
cium sulfate, CaS0 4 ), 5 pounds. 

These ingredients, in substantially these proportions, 
thoroughly ground, pulverized and mixed, are placed 
in the ordinary glass pot in a glass-house furnace and 
heated until entirely fused, with the result that they 
produce a glass that is translucent, opaque and free 
from specks; a glass which, when pressed into proper 
shapes for use with electric or gas light, has more 
than ordinary powers for reflecting and diffusing, 
and at the same time absorbing but very little of 
the flight with which it is used. 

I have discovered that three of the above ingredi¬ 
ents, to wit, cryolite, aluminum oxid and plaster of 
Paris, when used together in substantially the pro¬ 
portions herein set forth, have the effect of clouding 
or rendering translucent and at the same time opaque, 
the ordinary crystal glass which would result from 
the mixing of the other ingredients of the batch or 
mix hereinbefore specified. The result of the use 
of the three ingredients, cryolite, oxid of alumina, 
and plaster of Paris, as affecting the translucency, the 
opacity, and the diffusive and deflective powers of 
the glass manufactured from the ingredients herein 
specified, is similar with any batch that will produce 
the ordinary crystal glass, whether made with a lead 
or a lime base, provided additional ingredients equiva¬ 
lent to niter and borax are used therewith. 

The batch set forth totals 614 pounds. The alu¬ 
minum in the batch is contained in the aluminum oxid 
(AI 2 0 3 ) and in the cryolite (Na 3 ALF 6 ), the per¬ 
centage of aluminum in these two compounds being 


73 


respectively 52.9% and 12.9%, so that in the 60 
pounds of aluminum oxid there are 31.74 pounds of 
aluminum, and in the cryolite there are 2.58 pounds 
of aluminum, a total of 34.32 pounds or 5.59% of 
the entire batch. The fluorin in the batch is contained 
in the cryolite which is 54.3% fluorin so that in the 
20 pounds of cryolite there are 10.86 pounds of flu¬ 
orin or 1.77% of the entire batch. The plaster of 
Paris (CaS0 4 ) comprises 5 pounds or .81% of the 
entire batch, the amount of sulfur in the plaster of 
Paris being 23.6% thereof or .19% of the total batch. 

As the aluminum, fluorin and sulfur are the color¬ 
ing or opacifying agents, other compounds containing 
them might be substituted, provided an adjustment 
be made to secure the proper amounts of said ele¬ 
ments as heretofore set forth. The amount of the 
opacifying agents may also be varied depending upon 
the opacity desired. 

I claim: 

1. A batch for producing glass consisting of a foun¬ 
dation mixture capable when fused of producing a 
substantially colorless (glass, so combined with a sul¬ 
fate and aluminum and fluorin compounds that the 
resulting glass will contain undecomposed sulfate. 

2. A batch for producing glass consisting of a 
foundation mixture capable when fused of produc¬ 
ing a substantially colorless glass, combined with a 
sulfate and with aluminum and fluorin compounds and 
free from any material tending to decompose the sul¬ 
fate at the working temperature of a glass furnace. 

1,143,885. Process for Making A Compound of 
Glass. Brookfield, June 22, 1915. 

This invention relates to a process for making a 
compound of glass much tougher and harder in qual¬ 
ity than ordinary glass now known, and which glass 
compound is particularly suitable for use as insul¬ 
ators and other glass articles requiring a tough, non- 
fragile and durable quality. 



74 


In general the compound formed by this process is 
characterized by a large percentage of an oxid of 
one of the alkaline earths. It is well-known among 
glass manufacturers that the presence of calcium oxid 
(CaO) or lime imparts a tough quality to glass, but 
heretofore it has been impossible to increase the per¬ 
centage of lime in the glass to any great extent. If 
too large a proportion of lime is added as one of 
the original ingredients of the batch which is to be 
formed into the glass, it will render the batch in¬ 
fusible at the temperatures ordinarily employed, or 
if the batch is partially fused it is found that the 
lime collects in irregular, unfused lumps throughout 
the mass, destroying its homogeneity and resulting- 
in an almost worthless product. Although among 
glass manufacturers the recipes for the batch are 
mostly empirical, it is believed that at present not 
more than ten to fifteen per cent of the batch is lime, 
either in the form of pure calcium oxid or in the 
form of a salt which breaks up into the oxid dur¬ 
ing fusion, and it is believed that any larger per¬ 
centage of lime in the batch than that above indi¬ 
cated would result in the worthless product above 
described. 

My process contemplates the progressive addition 
of the oxid to the other elements of which the glass 
is composed. 

Describing my process and the compound obtained 
thereby more particularly, I first obtain a finely pul¬ 
verized cullet which may be scrap glass of different 
descriptions and probably containing proportions of 
both lime and lead glass, or I may manufacture glass 
in the ordinary way and grind it into pulverized form. 
Of course if the cullet is manufactured, it will be 
preferable to obtain it by the lime glass process on 
account of the cheapness of the lime. Into the pul¬ 
verized cullet, presumably already containing as one 


75 


of its constituents as much lime as ordinary glass 
may possess, I mix thoroughly by any suitable me¬ 
chanical means a pulverized oxid of one of the al¬ 
kaline earths, for instance, calcium oxid (CaO) or 
lime. In place of pure lime I may, of course, add any 
of the usual salts or hydrates of the alkaline earths, 
provided they are capable of furnishing the oxid 
when fused in the mixed mass. For example, I may 
employ in the mixture ordinary powdered marble or 
chalk, calcium carbonate (CaCo 3 ), in place of lime, 
since this compound during the subsequent fusion of 
the mass apparently breaks down into the oxid (CaO) 
with consequent escape of carbonic acid gas (Co 2 ). 
The escape of gas from the fused mass, however, 
causes bubbles which may in some cases destroy the 
homogeneity of the resulting product. Consequently 
the use of the oxid of the calcium or other alkaline 
earth is preferred over the salts and hydrates. 

The cullet and the lime or its equivalent above de¬ 
scribed may be ground separately into their pulver¬ 
ized form and afterward mixed if desired, but I find 
it preferable to grind these ingredients together since 
a more intimate, uniform and thorough mixture is 
thus obtained. 

The mixture is then heated to approximately 2,500° 
F. for fusing or partially melting the same into a ho¬ 
mogeneous mass having the lime evenly distributed 
and thoroughly incorporated in the same. The pro¬ 
portion of lime in this heated mixture is preferably 
high enough to result in a semi-plastic, semi-liquid 
mass at the temperature stated, which is workable 
into shape for various glass articles. The material 
upon cooling may be either amorphous or devitrified, 
but at any rate, it is found to be of uniform char¬ 
acter throughout and a much tougher and harder prod¬ 
uct than ordinary glass. 


76 


The exact proportions of lime or its equivalent 
added to the mixture may vary within wide limits 
since any addition of lime whatever to the glass cul- 
let results in a tougher product than ordinary glass 
and the maximum limit is only that amount which will 
allow the heated mixture to sufficiently fuse together 
into a homogeneous mass workable into shapes, but 
obviously no silica is added to the ground cullet. I 
have found that suitable proportions for the mixture 
may be thirty pounds (30 lbs.) of lime or its equiva¬ 
lent, to every one hundred pounds (100 lbs.) of cul¬ 
let. 

If, during fusion, bubbles of gas escape, due to 
the presence of impurities or to the employment of 
salts in the mixture as before stated, the mass should 
not be allowed to cool until this bubbling ceases and 
the mass is quiescent. As this often requires a longer 
heating of the mass, and consequent greater expense, 
a further reason is seen for preferring the oxids in 
the original mixture over the carbonates or other 
salts. For the same reasons of economy the calcium 
compounds are preferred over those of the other 
more expensive alkaline earths such as barium, stron¬ 
tium, etc. 

The term fusion is used herein to indicate that 
blending or coalescence of the mixed materials, 
through melting or partial melting, into a homogene¬ 
ous mass. 

The difficulty of obtaining a uniformly fused mass 
has heretofore prevented the introduction of a larger 
percentage of the lime into the batch mixture in mak¬ 
ing glass, but in the present method of adding lime 
to the already obtained glass, we are able to manu¬ 
facture a glass compound having all qualities due to 
a larger percentage of lime, and yet of homogeneous 
structure. 


77 


What I claim is: 

1. The process of making a glass compound con¬ 
taining an excess of one ingredient, which comprises 
the steps of mixing with ground glass, containing the 
usual amount of said ingredient, a chemical compound 
of said ingredient such as will furnish the oxid there¬ 
of, and fusing the whole to incorporate this excess 
into the mass. 


1,151,911. Glass, Sullivan & Taylor (Assigned to 
Corning Glass Works), Aug. 31, 1915. 

This glass is intended for making union with metal¬ 
lic parts, as in electric incandescent lamps. It has 
a coefficient of expansion varying between .000012 
and .000017. 

A glass which is soft and relatively stable, possesses 
good vitrification, and remains viscid or pasty through 
a relatively wide temperature is made of the follow¬ 
ing composition: 


Si0 2 

Na 2 0 

K 2 0 

BaO 

A1 2 0 3 


42% 

19% 

5% 

19% 

15% 


Such a glass has a coefficient of expansion of 
.0000135 and a hardness of 630°C. 

We claim: 

1. A glass for the purpose stated having a linear 
expansion of more than .000012 and a hardness of less 
than 640° and containing barium oxid and alumina. 


No. 1,153,353. Batch for Semi-Opaque, Semi-Trans¬ 
lucent Glass. Stiefel (Assigned one-half to A. 
M. Neeper), Sept. 14, 1915. 

My invention relates to new and useful improve¬ 
ments in semi-opaque, semi-translucent white glass. 




78 


One of the principal objects of my invention is 
to produce semi-opaque, semi-translucent glass of 
whitish color, without fluorescence or fire and with¬ 
out the use of fluorin or a compound thereof. 

My invention consists of a semi-opaque, semi-trans¬ 
lucent whitish glass made without the use of fluorin 
or a compound thereof and the batch therefor. 

The batch for my improved glass consists of the 
ingredients commonly used for the production of 
crystal glass in connection with the use of nitrate of 
lime as one of the ingredients thereof, preferably 
consisting of sand, soda ash, lead oxide, nitrate of 
lime and suitable decolorizing agents; of an opacify¬ 
ing agent which does not contain fluorin and is not a 
compound thereof; and certain ingredients which are 
consistent with the above two classes of ingredients, 
which when heated in connection therewith are com¬ 
paratively inert but are productive of a gas when 
fused therewith which keeps the entire mass of the 
batch in gentle ebullition. 

Preferably the batch will consist of the following 
ingredients in substantially the following quantities by 
weight: sand, 60 parts; soda ash, 15 parts; lead oxid, 
15 parts; nitrate of lime, 3-1/2 parts; phosphate of 
magnesia, 3-1/2 parts or less ; carbonate of magnesia, 
3-1/2 parts; alum, 3-1/2 parts. Using 3-1/2 parts of 
phosphate of magnesia makes a comparatively opaque 
whitish translucent glass. If it is desired that the 
glass made have a greater degree of translucency, 
then the quantity of phosphate of magnesia may be 
reduced until the desired degree of translucency is 
attained; by adding a greater quantity than 3-1/2 
parts, by weight, to the batch the glass will become 
a white opaque glass. The phosphate of magnesia is 
introduced as a fine, white, dry powder. 

The batch substantially in the quantities above in¬ 
dicated being introduced into the melting pot of a 
glass furnace has heat applied to it until the fusible 


79 


ingredients of the batch are completely fused and 
volatile products escape. The application of heat 
to the batch has the effect of dislodging from the 
carbonate of magnesia carbonic acid gas; from the 
alum the gases composing the water contained in 
that compound, as well as the gases in the phosphate 
of magnesia. The escape of these gases during the 
fusion and hpating of the mass keeps the batch in 
a gentle constant state of ebullition and causes the 
phosphate of magnesia, which by the heat applied is 
transformed into fine particles of pyrophosphate of 
magnesia, to be distributed as fine solid particles 
through the fused mass, thereby imparting to the 
mass and the resultant glass made therefrom opacity 
and translucency. The absence of the fluorin or a 
compound thereof results in the glass, manufactured 
according to my invention, being entirely free from 
fluorescence or “fire” usually present in opal glasses. 

What I claim as my invention is: 

1. A batch for a semi-opaque, se'mi-translucent 
glass, consisting of a foundation batch to produce 
a crystal glass, in combination with phosphate 
of magnesia, and additional ingredients compara¬ 
tively inert and neutral to the foregoing ingredients 
of said batch, which upon the fusion thereof evolve 
gases which in passing 1 off keep said batch, while in 
a fused condition, in a condition of ebullition. 

2. A batch for a semi-opaque, semi-translucent 
glass, consisting of a foundation batch to produce crys¬ 
tal glass, one of whose ingredients is nitrate of lime, 
in combination with phosphate of magnesia and ad¬ 
ditional ingredients comparatively inert and neutral 
to the foregoing ingredients of said batch, which, 
upon the fusion thereof evolve gases which in pass¬ 
ing off keep said batch, while in a fused condition, 
in a condition of ebullition. 


80 


No. 1,158,922. Glaze, Enamel or Glass Composition. 
Hull, Nov. 2, 1915. 

My discovery and invention relates to glazing, 
enameling or glass manufacture, and has for its ob¬ 
ject the provision of the desired metallic constituent 
in glaze, enamel or glass in an effective, economical 
and safe manner. 

My discovery and invention consist^ in providing 
the metal constituent in its uncombined form. 

My discovery and invention is more particularly 
applicable to glazing of pottery ware, tile and earth¬ 
enware, in which a salt or other product of corrosion 
of or chemical action upon metal is used. 

Glazes, enamels and glass have long been made with 
the addition of some salt of a metal or other product 
of corrosion of or chemical action upon the metal, 
such as oxid of lead, carbonate of lead or white lead, 
or oxid of zinc, the function of these ingredients 
generally being to impart to the glaze, enamel or glass 
composition increased fusibility, or to impart to the 
finished product thereof increased strength, density, 
softness or luster. I have discovered that the metal 
itself may be incorporated in the glaze, enamel or 
glass, and that the metal itself will produce the ef¬ 
fect which the carbonate or oxid or other product 
of corrosion of or chemical action upon the metal will 
produce. While the metal constituent thus provided 
in its metallic form is a suitable substitute for the 
substances heretofore used, it affords a considerable 
saving, because the metal generally costs no more 
for a given weight than does the metal in combined 
form, since, as it seems, the metal, aside from the 
other elements combined with it in the combined form, 
is the active element; and the other elements are either 
driven off during the firing or heating or combined 
in the glaze without having any utility. Thus, taking 
carbonate of lead or white lead as an example, which 
is largely used as a constituent of glaze, enamel or 
glass, it seems that the carbon and oxygen combined 


81 


with the lead has no utility and performs no function 
in the glaze; but as is well known in the art, carbonate 
of lead or white lead costs substantially the same as 
thqj metallic lead, and commands substantially the 
same or a slightly higher price on the market; so that 
the potter or manufacturer in buying this ingredient, 
is obliged to pay for a certain weight of carbon and 
oxygen, or other extra substance, in the carbonate of 
lead, in order to obtain the effect of the amount of 
lead element in the ingredient, whereas, by using the 
lead in its metallic form, practically no other sub¬ 
stance is bought, and practically all of the ingredi¬ 
ent is useful in the glaze. Experience in connection 
with my discovery and invention has shown that this 
circumstance admits of the reduction of weight of 
this constituent from 25 to 50 per cent, and the re¬ 
sults attained are fully equal to those that have been 
obtained with the use of the white lead or other com¬ 
bined form of or product of corrosion of or chemical 
action upon the particular metal desired to be used 
in the glaze, enamel or glass. 

Where carbonates or oxids or other combined forms 
of products of corrosion of or chemical action upon 
the materials have been used, they have been obtained 
in finely pulverized condition so that they are readily 
suspended in the liquid mixture of the glaze, and thus 
uniformly distributed throughout the glaze on the 
ware as the ware is dipped into the glazing mixture, 
or as the mixture is applied to the ware with a brush 
or otherwise. In utilizing the metal itself I provide 
it in finely pulverized form, preferably in a substan¬ 
tially impalpable powder, and find that it is capable 
of suspension in the mixture substantially as uni¬ 
formly as the ingredient in combined form would 
be; and that, when the proper proportion of the metal 
is used, the finished product will be found uniform 
in appearance and without any appearance of the 
metal. In providing the finely pulverized metal, es¬ 
pecially with respect to lead, it is preferably obtained 


82 


as a result of a process of comminuting or granulat¬ 
ing lead to be corroded in the manufacture of car¬ 
bonate of lead or white lead. The greater proportion 
of white lead is used in the making of paint and 
similar products, while a less but important proportion 
has been used for the metallic constituent of glazes, 
enamels or glass. For the purposes of corrosion, the 
lead need not be so finely divided, and a comminut¬ 
ing process which has been found thoroughly prac¬ 
ticable for corroding purposes consists in the ejection 
of molten lead in a small jet into a chamber where it 
is suddenly condensed and falls in the form of a rather 
fine powder or small granules. At the same time 
this moderately fine powder is produced there is a 
much finer powder of the lead, which is deposited 
along with the coarser particles; and by introducing a 
fine screen, which allows the fine powder to pass 
through but retains the coarser powder or granules. 

I claim: 

1. A glaze, enamel or glass composition containing 
as an ingredient a metal in its metallic state and in the 
form of a substantially impalpable powder produced 
by condensation of the metal in a finely divided form. 

No. 1,166,922. Method and Batch or Mixture For 
Making Illuminating Glass. Meara (Assigned to 
Gill & Co.), Jan. 4, 1916. 

In the manufacture of glass for illuminating pur¬ 
poses, such as electric and other similar shades and 
globes, it is desirable to employ a process and batch 
which will produce a glass having a snow white ap¬ 
pearance and which will be translucent to a high de¬ 
gree, and will, at the same time, be not clear, and 
adapted to transmit light without the yellow or red¬ 
dish color, known as fire, the glass in these respects 
distinguishing from the well-known opal glasses, 
which are either substantially opaque and known as 
milk glass or are to some degree translucent, in which 
case the coloring known in this art as fire is always 
noticeable when light is observed through the glass 


83 


My invention farther consists of a novel process 
and batch, which will produce a glass having a wlihe: 
luminous appearance when transmitting light, with 
such light diffused in a manner pleasing and restful 
to the eyes, the giass being subject to a minimum 
amount of breakage upon the application of hea+, as 
well as a minimum loss of illuminating power, while 
the so-caLled specks or bubbles heretofore existing in 
glass of this general character, wherein a fluorin com¬ 
pound or fluorid is employed, are substantially obliter¬ 
ated or eliminated in my process and batch. 

In carrying out my invention, I first take a batch 
or mixture, the preferred ingredients being hereinaf¬ 
ter particularly pointed out, and fuse the same to a 
preferred temperature, the result of my novel pro¬ 
cess and the manipulation of the glass batch result¬ 
ing in a product wherein the so-called specks or bub¬ 
bles are practically obliterated or eliminated. If de¬ 
sired, I may stop the heating operation of the batch 
at such a period as will be short of the production of 
complete transparency and the obliteration of the 
specks or bubbles from the glass, the glass tending 
to return to its colorless crystal stage, if the operation 
is continued too long, but I prefer to continue the fus¬ 
ing or heating operation until the obliteration of said 
specks is nearly completed. 

In practice, I have found that good results are ob¬ 
tained in a furnace working at a temperature of ap¬ 
proximately between 2,500 and 3,000 degrees F. and 
the length of time of the operation generally required 
is from twenty-one to twenty-four hours. 

The ingredients from which the batch or mixture 
is composed are the following, combined in substan¬ 
tially the proportions stated : Sand, 100 lbs.; alumina, 
30 lbs.; oxide of lead, 22 lbs.; silex, 12 lbs.; soda, 37 
lbs.; borax, 6 lbs.; oxid of arsenic, 3 lbs.; oxid of 
antimony, 1 1/4 lbs.; common salt, 1 1/2 lbs.; salt 
cake (crude sodium sulfate), 1 1/2 lbs.; crystallized 
Glauber salts, 2 lbs.; gypsum, 1 1/2 lbs. Said in- 


84 


gredients are fused in any suitable manner and form, 
when so combined, a white translucent glass which 
transmits, when formed into a sheet, globe or shade, 
light of a white color and free from yellow, red or 
opalescent rays. 

The proportions of the ingredients of the mixture 
may be changed, if desired or required, according to 
the use of the glass and its purposes, but for the 
manufacture of globes or shades for lamps, substan¬ 
tially the above formula of proportions has been! 
proved to be most satisfactory. 

I desire to call special attention that in my novel 
foregoing process and batch, I entirely dispense with 
the use of a fluorid or a fluorin compound, as has been 
heretofore employed, and preferably employ the fore¬ 
going ingredients, whose relative proportions may vary 
somewhat, depending upon the variation in the basic 
or foundation glass. I preferably manipulate the 
glass batch composed of the foregoing ingredients, 
so that the duration of operation and the degree of 
heat may be regulated so as to substantially obliterate 
or eliminate the so-called specks or bubbles, but I do 
not desire to be limited to any exact duration of 
operation or to any exact degree of heat as this may 
be modified or compensated for by variations in the 
mixture or the length of time of the operation, as 
will be apparent to those skilled in this art. 

I am aware of the reissued patent to Macbeth, No. 
13,766, granted July 7th, 1914, and my present in¬ 
vention is clearly differentiated therefrom, since I 
employ no fluorid or fluorin compound, and no in¬ 
gredient the equivalent thereof, as is evident. 

It will now be apparent that I have devised a novel 
and useful method and batch or mixture for making 
illuminating glass, which embodies the features of ad¬ 
vantage enumerated as desirable in the statement of 
the invention and the above description, and while I 
have, in the present instance, described a preferred 


85 


embodiment thereof which will give in practice satis¬ 
factory and reliable results, it is to be understood that 
the same is susceptible of modification in various par¬ 
ticulars without departing from the spirit or scope of 
the invention or sacrificing any of its advantages. 

I claim: 

1. The herein-described method of manufacturing 
illuminating glass, which consists in fusing together 
a foundation mixture capable of making substantially 
colorless clear glass, said mixture comprising sand, 
alumina, oxid of lead, silex, soda, borax, oxid of ar¬ 
senic, oxide of antimony, common salt, salt cake, crys¬ 
tallized Glauber salts and gypsum, and the heating 
operation being stopped at such a period that the 
specks in the glass are substantially eliminated. 

2. The herein-described method of manufacturing 
illuminating glass, which consists in fusing together 
a foundation mixture capable of making substantially 
colorless clear glass, said mixture comprising sand, 
alumina, oxid of lead, silex, soda, borax, oxid of 
arsenic, oxid of antimony, common salt, salt cake, 
crystallized Glauber salts and gypsum, and the heating 
operation being stopped before the glass returns to a 
clear glass stage and at such a period that the specks 
in the glass are substantially eliminated. 

3. The herein-described mixture for manufacturing 
illuminating glass, composed of sand, alumina, oxid 
of lead, silex, soda, borax, oxid of arsenic, oxid of 
antimony, common salt, salt cake, crystallized Glauber 
salts and gypsum, fused together. 

No. 1,191,630. Composition of Glass, Weintraub 
(Assigned to General Electric Company), July 
18, 1916. 

The present invention relates to envelops of quartz 
and in particular to an improved seal between quartz 
and a metallic conductor. 

Patent No. 910,969 describes a seal for quartz con¬ 
tainers in which a metallic conductor is sealed into a 



86 


glass, the composition of which merges gradually into 
quartz with a progressively decreasing proportion of 
basic constituents of the glass, 

I have found when experimenting with a large num¬ 
ber of glasses that a sodium-magnesium boro-silicate 
which can be obtained in the market as “low expansion 
glass,” has the property of forming fusions with silica 
in any proportion with the formation of exceptionally 
strong tough glass for all proportions. The glasses 
thus produced are amorphous masses devoid of crys¬ 
tallization and have all the desirable properties which 
are characteristic of what is termed a “glass.” 

My invention comprises new glasses of high melt¬ 
ing point and low coefficient of expansion and richer 
in silica than any glasses produced so far, that is, in' 
excess of about 73% silica. In view of the fact that 
these glasses are tough, and free from crystallization 
they could be used for any purposes where the above 
enumerated properties are desirable. 

According to one method of carrying out my in¬ 
vention, low expansion glass is intimately mixed with 
progressively larger quantities of silica to make a 
series of melts. A boro-silicate suitable for this pur- 
pos)e has the following composition: Silica, Si0 2 , 
72 to 73 per cent; magnesium oxid, MgO, 3 to 4 
per cent; boric anhydrid, B 2 0 3 , 11 to 12 per cent; 
sodium oxid, Na 2 0, 12 to 13 per cent. It will be un¬ 
derstood, of course, that this composition is illustra¬ 
tive. Potassium might be substituted for sodium. 

A glass of the above composition or its equivalent, 
is very finely powdered and to separate portions 
ground quartz is added to the extent of about 15, 30, 
50, 70 and 85% of quartz to 85, 70, 50, 30 and 15% 
respectively of glass. The proportions need not be 
strictly adhered to but are given for the purpose of 
illustration. These mixtures are fused to form glasses 
having an excess of 73% silica, as progressively larger 
portions of quartz are incorporated in the several por- 


87 


tions of low expansion glass. These glassy mixtures 
have a coefficient of expansion intermediate between 
3.5xlO'V which corresponds to low expansion glass, 
and about .6xl0' 6 , which corresponds to quartz. Said 
glasses are built up at the end of the quartz tube by 
means of the oxygen blowpipe or arc so as to secure 
a progressive change of composition from silica to 
low expansion glass. For example, to the end of a 
quartz tube a ring or layer of the vitreous mixture 
comprising 85% of quartz and 15% of glass is ap¬ 
plied and heated so as to unite and intermingle it with 
the quartz tube. This heating causes a further blend¬ 
ing of the two materials so that the composition 
changes by almost imperceptible stages from pure 
quartz to the material containing an appreciable 
amount of admixture. This process is then repeated 
with a vitreous material containing a lower amount of 
admixed silica. By working in this way the basic 
constituents of the boro-silicate are progressively in¬ 
creased when receding from the region of pure silica 
until finally the tube is closed with a portion of low 
expansion glass having the above indicated composi¬ 
tion into which a tungsten or molybdenum wire is 
sealed in the usual manner. A low expansion, boro- 
silicate glass of the above composition has a coeffici¬ 
ent of expansion of about 3.5xl0' 6 . I have found 
that tungsten, W, or molybdenum, Mo, which has 
about the same coefficient of expansion is readily 
wet by this glass and may be used to make a perfectly 
gas-tight seal as described by me in my Patent No. 
1,154,081. 

In case it is desired to use a leading in wire con¬ 
sisting of platinum, it is necessary to join by 
fusion to the boro-silicate other glasses having a pro¬ 
gressively higher coefficient of expansion until the co¬ 
efficient of ordinary lead glass is approached. The 
seal may then be completed with ordinary lead glass 


88 


into which platinum wire may then be inserted by 
fusion in the ordinary manner. Glasses having these 
intermediate coefficients of expansion may be readily 
obtained in the market. Ordinarily it is desirable to 
use as many as three or even more layers of glass in¬ 
termediate between the boro-silicate glass and the lead 
glass which has a coefficient of expansion of 9x1 O' 6 . 

1. A tough, strong, glassy material consisting of 
combined basic material and the oxids of boron and 
Jsilicon, the last oxid being materially in excess of 
73%, said material having a thermal coefficient of ex¬ 
pansion less than about 3.5xl0" 6 . 

2. A tough, strong glass consisting of the oxid 
of an alkali metal, magnesium, boron and silicon, the 
silicon dioxid being in excess of about 73%, said glass 
having a thermal coefficient of expansion less than 
3.5xl0' 6 . 


No. 1,192,048. Glass Batch or Mixture. Elliott 
(Assigned to Macbeth-Evans Glass Co.), July 25, 
1916. 

This invention relates to an improved form of 
glass, having properties which give it special value for 
use in diffusing and distributing artificial light. These 
new and valuable properties are secured by the use of 
certain ingredients in the raw materials, or “batch” 
of which the glass is formed by the usual process of 
fusion. 

A brief statement of the chemical and physical 
principles involved in glass making will facilitate a 
clear comprehension of the improvements which con¬ 
stitute my invention. 

Glass, as known in commerce, is a mixture of sili¬ 
cates, holding more or less silica in solid solution, with 
the frequent presence of metals or elements in col¬ 
loidal suspension. 



89 


The chief physical characteristics of clear or cry¬ 
stal glass are transparency, hardness, brittleness and 
elasticity. Its chief chemical characteristic is resist¬ 
ance to solvents. 

Glass loses its transparency and assumes a white 
translucency under any one or more of the follow¬ 
ing conditions: (A) when one or both surfaces are 
roughened, causing diffuse reflection therefrom; (B)' 
when minute globules or particles of air, gas, trans¬ 
parent crystals, or glass of different refractive index 
are distributed throughout the mass; (C) when par¬ 
ticles of white matter more or less opaque are scat¬ 
tered through the mass. Glass known in commerce as 
“opal,” “opalescent” and “alabaster,” and used for 
the diffusion of artificial light, belong to class B, and 
are .produced by the use of phosphates, or fluorids, 
in the “batch.” It is well established that the minute 
particles above mentioned as producing glass “B” are 
ultra-microscopic in size, being comparable to wave 
lengths of light in their dimensions. This is proven 
by the fact that glass of this type shows selective 
absorption of transmitted light, the shorter waves be¬ 
ing usually absorbed, thereby giving an orange color 
to the glass when thus viewed. This phenomenon is 
known in the industry as “firing.” Such display of 
color is objectionable, but can be prevented in this 
type of glass only by increasing its density or opacity, 
i. e., reducing the translucency of the glass, which is 
objectionable on account of greater absorption of light 
and consequent less efficiency. This type of glass also 
possesses a characteristic milk-white, glassy appearance 
by reflected light, strongly resembling glazed porce¬ 
lain; whence it was formerly sold as “milk-china,” is 
called “Milch-glass” in German, and is still frequently 
referred to as “porcelain” when in the form of a 
lamp shade. 

In my improved glass I secure the following ad¬ 
vantages: (A) complete elimination of “firing” due 


90 


to selective absorption; (B) substantially perfect dif¬ 
fusion of transmitted light with minimum absorp¬ 
tion; (C) an apparent texture and color, both by 
transmitted and reflected light, almost exactly similar 
to natural alabaster, and free from the peculiar milk- 
glass quality. Such glass is pre-eminently suited to 
the production of bowls and plaques now largely used 
for semi-indirect lighting, and is also equally valu¬ 
able for light-dififusing globes and shades. 

I am aware that a glass resembling mine has been 
commercially produced, and is the subject of Letters 
Patent No. 1,097,600, dated May 19th, 1914; but 
this glass is objectionable for some purposes, in that 
visibly large particles or specks of a white opaque 
matter are scattered through it, which show as black 
spots and specks when the glass is seen by transmitted 
light. These specks are not present in glass produced 
from my improved batch. The glass above referred 
to also requires careful manipulation in the making, 
as set forth in the patent, whereas my batch requires 
no special treatment in the fusion. 

I secure the peculiar qualities of my glass by a com¬ 
bination of methods B and C, hereinbefore described, 
i. e the matrix of clear glass has suspended therein 
glass particles of both ultra-microscopic and micro¬ 
scopic size. The ultra-microscopic particles change 
the glass matrix from a transparent to a translucent 
condition, while the microscopic particles prevent the 
selective absorption of the rays; the two effects com¬ 
bining to produce the alabaster appearance. 

To produce the ultra-microscopic particles I use 
aluminum and fluorin compounds in certain propor¬ 
tions as hereinafter specified. 

To produce the microscopic particles I use a sul¬ 
fate. I have found that if sulfates be added to a 
batch adapted to form clear glass, the resultant pro¬ 
duct closely resembles the mineral known as moon¬ 
stone. It is believed that the sulfate is not decom- 


91 


posed by the silica and alkalis forming such batch, 
and that the fine particles thereof are simply held in 
suspension, producing the effect above stated. If now, 
the density, or opacity, of such glass be slightly in¬ 
creased by the addition of the ultra-microscopic par¬ 
ticles producible by the use of aluminum and fluorin 
compounds in certain proportions, the glass takes on, 
all the desirable properties before enumerated. 

I have found the following batch to give good re¬ 
sults: (1) sand 700, soda 200, pearl ash 100, niter 50, 
antimony 10. To which I add: (2) feldspar 200, 
cryolite 55, aluminum sulfate 15. 

Any batch capable of producing clear or colorless 
glass may be used in lieu of formula No. 1, as my 
improvement consists in adding to a batch adapted to 
produce clear or crystal glass, a sulfate, an aluminum 
compound and a fluorin compound. 

It will be understood that the invention is not lim¬ 
ited as regards the relative proportions of the sul¬ 
fate and the aluminum and fluorin compounds, as good 
results can be obtained when the proportions of such 
ingredients vary widely from those stated. But it is 
preferred that the aluminum and fluorin compounds 
should be added in such relative proportions that the 
weight of the element fluorin in the batch should not 
be less than that of the element aluminum. 

Any sulfat e which will not be affected by or af¬ 
fect the silica and alkalis of the batch may be em¬ 
ployed. Good results can be obtained in the use^ of 
sulfates of aluminum, magnesium, calcium, barium, 
strontium, lead, zinc, and other metals which will not 
produce color in the glass. 

The sulfates may be added in any desired propor¬ 
tions from one per cent (1%) up of the total weight 
of the batch, since any excess will simply float on 
the surface of the molten glass as before stated. 

It is old in the manufacture of opal glass to add 
barium sulfate or barium carbonate to the batch in 
order to increase the index or refraction, and there- 


92 


by the brilliancy of the resulting glass, but this ef¬ 
fect cannot be produced in using barium sulfate un¬ 
less the latter is discomposed by the use of a reduc¬ 
ing agent, as charcoal. It is characteristic of my im^ 
provement that the sulfate is not reduced but remains 
in a state of suspension furnishing the microscopic 
particles found in the resulting glass. 

I claim : 

1 A batch for producing glass consisting of a 
foundation mixture capable when fused of producing 
a substantially colorless glass, combined with a sulfate 
‘which will not affect or be affected by silica and al¬ 
kalis in the batch, and aluminum and fluorin com¬ 
pounds in such proportions that the weight of the 
element fluorin is not materially less than the weight 
of the element aluminum and free from any material 
tending to decompose the sulfate at the working tem¬ 
perature of a glass furnace. 

2. A batch for producing glass consisting of a 
foundation mixture adapted to produce colorless glass, 
to which is added compounds containing a sulfate, 
which will not affect or be affected by silica and al¬ 
kalis in the batch, compounds containing aluminum, 
and compounds containing fluorin, the total aluminum 
and fluorin contents being approximately equal in 
quantity and the sulfate being in such quantity as to 
leave suspended in the final melted mass undecom¬ 
posed particles of sulfate, substantially as described. 


No. 1,192,474. Glass. Taylor (Assigned to Corning 
Glass Works), July 25, 1916. 

My invention relates to a composition for the pro¬ 
duction of a glass of a low expansion co-efficient, 
and inasmuch as one of the uses had in view for this 
glass is the manufacture from it of culinary vessels, 
my invention also contemplates the production of a 
glass of a low expansion and of high stability. 



93 


Glasses of very low co-efficient expansion can be 
obtained by formulae now known, but the difficulty 
experienced in such compositions is that if their ex¬ 
pansion co-efficient is sufficiently low for the practical 
purposes, their temperature of fusing is so high as to 
preclude their economical working, and prevent their 
use for the manufacture of ware which I have in 
mind. I have discovered, however, that the addition 
of a smalL amount of lithia reduces the temperature 
of fusion of a glass mixture to a very great degree, 
and that this is so pronounced that although lithia 
has a high expansion factor, still it can be used ii> 
such small quantities as not to appreciably increase 
the expansion co-efficient of the mixture, while at the 
same time, materially reducing the fusing tempera¬ 
ture. I have further discovered that lithia in the com¬ 
position which I herein describe is of value in increas¬ 
ing the stability of the glass, although the glass here¬ 
in referred to is a boro-silicate of very low expansion. 
Glasses of such compositions, especially when of high 
boric acid contents, are generally unstable, and sub¬ 
ject to decomposition. 

The following are examples of the compositions of : 


several glasses made in 

accordance with this 

inven- 

tion : 

A. 

B. 

C. 


% 

% 

% 

Si0 2 

71 

75 

70 

B 2 0 3 

28 

15 

13 

Li 2 0 

1 

1 

9 

A1 2 0 3 


5 

2 

Na 2 0 


4 


Sb 2 0 3 



6 


The expansion co-efficient of composition “A” 
above named, I have found to be .0000029, of B, 
.0000040, and of C, .0000056. It will be noted that 
all of the above compositions contain a compara¬ 
tively large per cent of boric oxid; and that all of 


94 


them are boro-silicates. Glasses made from composi¬ 
tions of the formulae above given are extremeLy use¬ 
ful in the manufacture of glass articles exposed to 
extreme variation of temperature and to attacks by 
steam or other chemical action, this being by reason 
of their low co-efficient of expansion and their 
stability. 

The presence of the alumina in compositions B and 
C is useful in preventing crystallization during melting 
and working. 

I claim: 

1. A glass containing silica, boric oxid and lithia, 
in the proportions specified, and having a co-efficient 
of expansion of less than .0000056. 

2. A glass containing silica, boric oxid, lithia and 
alumina and having a co-efficient of expansion of less 
than .0000056. 


No. 1,214,202. Glass. Macbeth (Assigned to Mac- 
beth-Evans Co.), Jan. 30, 1917. 

The invention relates to an improvement in glass 
intended primarily for use in the manufacture of 
blown illuminating ware such as shades, globes, and 
the like, although suitable for use in pressed ware both 
for illuminating and other purposes. The invention 
has for its principal objects; the provision of a glass 
which in light transmitting ’properties lies between 
milk glass which is too dense and glass made under 
my Reissue Patent No. 15.766. wHch is not dense 
enough where the shades or globes are thin and the 
light intense; the provision of a glass of the character 
specified which, when used in a thin shade, will pre¬ 
sent a white luminous appearance, permitting a proper 
illumination by the transmitted light without showing 
the illuminating element; and the provision of a glass 
which is cheap, easily worked, without a red or yel¬ 
low tint, and capable of withstanding a very high 
temperature without breaking. 



95 


The foundation batch which I prefer to employ is 
as follows: 


Sand 
Potash 
Zinc oxid 
Borax 
Salt 


1000 parts 


190 “ 
240 “ 
66 “ 
5 “ 


The foregoing batch, which aggregates about 1,500 
parts, if used without coloring ingredients, will pro¬ 
duce a substantially colorless clear glass. Various 
substitutes for the elements might be used to form this 
clear glass batch, but the ones given are preferred. 

To the foregoing clear glass batch of 1,500 parts 
are added the coloring or opacifying ingredients com¬ 
prising preferably the following compounds and quan¬ 
tities : 

Hydrate of aluminum 190 p^rts 

Fluorspar 135 “ 

Sodium silico fluorid 150 “ 

The clear glass batch with the foregoing coloring 
compounds are thoroughly mixed together and melted 
at a temperature of from 2,700° F. to 2,800° F. 

The hydrate of aluminum (A1 2 H ! 6 0 6 ) contains 

65.4% of oxid of aluminum (A1 2 0 3 ) and the per¬ 
centage of aluminum is 34.6%, so that the 190 parts 
of aluminum hydrate has an aluminum oxid content 
of 124.2 parts and an aluminum content of 65.7 parts. 
As the aluminum oxid is the coloring agent, other 
compounds containing the oxid, such as china clay and 
feldspar might be used instead of the hydrate, if an 
adjustment were made so as to secure the proper! 
amount of the coloring agent. 

The fluorspar (CaF 2 ) contains 48.7% of fluorin, 
so that in the 135 parts of fluorspar there is 65.7 
parts of fluorin. Other fluorin compounds might be 
used, such as cryolite, if an adjustment were made to 
secure the proper amount of fluorin. 


96 


The sodium silico fluorid (Na 2 SiF 6 ) contains 
60.6% of fluorin so that in the 150 parts of this com¬ 
pound there are 90.9 parts of fluorin. Some other 
fluorid might possibly be substituted for the sodium 
silico fluorid if an adjustment were made to secure 
fluorin content in the fluorspar and sodium silico 
fluorid is 65.7 parts plus 90.9 parts or 156.6 parts. 

It will be understood that, aside from the substitu¬ 
tion of equivalent compounds for those above indi¬ 
cated, the proportions of the elements might be modi¬ 
fied to a considerable extent and still produce sub¬ 
stantially the same glass as that produced when the 
exact formula as above set forth, is employed. For 
instance, the aluminum oxid content may be varied 
between 80 and 160 parts, the fluorspar between 100 
and 170 parts, and the sodium silico fluorid between 
100 and 200 parts. The formuLa and proportions 
as above set forth, are, however, the ones which are 
preferred by me and which have produced the glass 
having the qualities referred to and also stated later. 
The glass as produced from the foregoing formula 
will stand a very high temperature without breaking, 
such quality being particularly advantageous when the 
glass is used in connection with high power nitrogen 
and gas lamps giving out an intense heat. The glass 
is also desirable with such high power illuminating 
elements since it diffuses the Light without permitting 
the lighting element to be seen, and this is the case 
even with a relatively thin blown shade or globe. 
At the same time, the glass permits of the passage 
of a large percentage of the light so that a proper 
illumination is secured by the transmitted light, such 
as could not be secured with the relatively dense milk 
glasses heretofore known in the prior art. In appear¬ 
ance, the glass is white and Luminous and without 
the objectionable yellow or brown tinge characteris¬ 
tic of opal glasses. The glass furthermore, is very 
easily worked and relatively cheap. 


97 


Claims: 

1. A glass formed by fusing together a mixture 
containing approximately the following proportions: 
1,500 parts of foundation batch capable of making 
substantially clear glass, 124 parts of aluminum oxid, 
135 parts of fluorspar and 150 parts of sodium silico 
fluorid. 

2. A glass formed by fusing together a mixture 
containing approximately the following proportions: 
1,500 parts of foundation batch capable of making 
substantially clear glass, 124 parts of aluminum oxid, 
135 parts of a fluorid containing about 50% by weight 
of fluorin, and 150 of sodium silico fluorid. 


No. 1,234,457. Process of Making Window Glass 
and Hydrochloric Acid. Glaeser (Assigned to 
G. T. Bishop), July 24, 1917. 

The present invention relates to a method of mak¬ 
ing window glass with hydrochloric acid as a by¬ 
product, or it may be considered as a method of mak¬ 
ing hydrochloric acid with window glass as a by¬ 
product, since in either case these two compounds are 
obtained from the present method. To the accom¬ 
plishment of the foregoing and related ends, said in¬ 
vention, then, consists of the means hereinafter set 
forth and particularly pointed out in the claim. 

The following description sets forth in detail one 
approved method of carrying out the invention, such 
disclosed mode, however, constituting but one of the 
various ways in which the principle of the invention 
may be used. 

The ordinary window glass is substantially a cal¬ 
cium-sodium-silicate, which is usually prepared by fus¬ 
ing a mixture of sand, lime or lime-stone, with sodium 
carbonate. I have found that by heating together in 
an open kiln a mixture of sand, lime or lime-stone, 
sodium chlorid, and coke in the presence of water 
and temperature of approximately 800° C. that a 
very good grade of window glass can be obtained, and 



98 


also a relatively pure hydrochloric acid. This mixture 
should be heated for about two hours at the highest 
temperature below which the sodium chlorid in the 
mixture will not fuse, which is approximately 800° 
C. under ordinary atmospheric conditions. 

By the heating of this mixture the sand-calcium 
chlorid-coke mixture is completely decomposed with 
the formation of a calcium silicate and with the forma¬ 
tion of hydrochloric acid gas, which is of course, 
given off. The various reactions which take place 
without the addition of coke during this heating may 
be illustrated as follows: 

(1) c+o=co 

(2) 2NaCl+C0=Na 2 0+Cl 2 +C 

(3) Cl 2 +H 2 0=2HCl+0 

(4) C (from (2))+0 (from (3))=CO 

Thus: 

2Si0 2 +Ca0+2NaCl+C+0+H 2 0= 

CaSi0 8 + , Na 2 Si0 8 ++2HC1+CO 

Or the reactions may be indicated: 

(1) Ca0+2NaCl=CaCljJ r Na 2 0 

(2) Si0 2 +Na 2 0=Na 2 Si0 3 

(3) C+0=CO 

(4) CaCl 2 +CO=CaO+Cl 2 +C 

(5) Si0 2 +CaO—CaSi0 3 

(6) C1 2 +H 2 0—2HC1+0 

(7) C (from 4)-fO (from 6)=CO 

Thus: 

2Si0 2 +Ca0+2NaCl+C+0+H 2 0= 

CaSi0 3 +'Na 2 Si0 3 ++2HCl+CO 

The addition of coke is essential in order to insure 
quick and complete decomposition of the salt. With¬ 
out coke a higher temperature must be employed, but 
even then the decomposition proceeds only very slowly 
and is incomplete. In the former case the decompose- 


99 


tion is effected by the action of the carbon monoxid 
'formed upon sodium or calcium chlorid (compare 
with equations shown above) ; while in the latter case 
—if coke is omitted—decomposition of the chlorid is 
caused by the action of oxygen upon sand-sodium or 
calcium chlorid mixtures, as is shown by the follow¬ 
ing equations: 

1. CaO+2NaCl=CaCl+Na 2 0 

2. Si0 2 +CaCl 2 +0=CaSi0 3 +Cl 2 

Or the reactions may be indicated: 

1. SiO 2 +CaO=CaSi0 3 

2. Si0 2 +2NaCl+0-Na 2 Si0 3 +Cl 2 

I have found, as stated before, that carbon monoxid 
reacts upon sand—sodium chlorid mixtures much 
more -quickly and efficiently than oxygen, insuring 
complete decomposition of the salt used. 

It is not important as to whether Lime or lime¬ 
stone be used in the mixture, the reactions being simi¬ 
lar in either case, and if lime-stone is used carbonic 
acid being produced in addition to the other products. 

The various amounts of each material which will be 
required in the mixture may be readily calculated from 
the foregoing reaction equations, but I have found 
that a suitable mixture consists of 100 parts sand, 
41 parts sodium chlorid, 26 parts of lime-stone, and 
about 15 parts of coke, which will be mixed in any 
suitable apparatus such for example as the ball mill, 
and then slowly and continuously fed into a rotary 
kiln. If the kiln is not of the rotary type, then it 
will be necessary to supply some means for stirring 
or agitating the mixture during the heating in order to 
secure a homogeneous product. 

As will be seen from the foregoing reaction equa¬ 
tions, the chlorids are decomposed with the liberation 
of hydrochloric acid and the formation of free bases 
which combine at once with the sand to produce a 


100 


double silicate of sodium and calcium of substantially 
the same chemical composition as window glass. The 
exact composition may, of course, be varied by chang¬ 
ing the proportions of the mass to be furnaced. The 
hydrochloric acid formed may be collected in suitable 
devices while the calcium sodium silicate is run into 
,a glass melting furnace and fused. 

The foregoing process is a simple one by which 
both hydrochloric acid and window glass may be 
produced from relatively inexpensive and abundant 
materials. 

Other modes of applying the principle of my in¬ 
vention may be employed instead of the one explained, 
change being made as regards the process herein dis¬ 
closed, provided the step or steps stated by the follow¬ 
ing claim or the equivalent of such stated step or steps 
be employed. 

I claim: 

In a process of making window glass, the step 
which consists in heating a mixture of sand, lime, 
sodium chlorid and carbon at a temperature of ap¬ 
proximately 800° C. in the presence of steam in ah 
open kiln. 

No. 1,245,487. Opaque Semi-Translucent Glass. 
Miller (Assigned to Macbeth-Evans Glass Co.), 
Nov. 6, 1917. 

This invention has reference to the production of 
a new opaque semi-translucent glass. 

It is the object of my invention to produce a semi¬ 
opaque, semi-translucent glass by use of a new com¬ 
bination of ingredients fused upon a plan resulting in 
a new semi-opaque, semi-translucent glass. 

The invention consists of a new semi-opaque, semi- 
translucent glass, produced by new ingredients com¬ 
bined in a novel way and fused in accordance with 
newly discovered procedure, which if followed, en¬ 
ables the color, texture and other properties of the 




101 


product to be controlled to a greater extent than here¬ 
tofore. More particularly my invention consists in 
the use of a strontium-sulfur-oxygen compound in 
connection with a compound of an alkaline metal or 
earth with fluorin and a highly refractory material 
fused with the usual ingredients of a lead glass batch, 
substantially in the proportions and in the manner 
hereinafter more specifically described. 

I have found that by the use of the usual batch for 
lead glass, consisting substantially of sand, soda and 
an oxid of lead, preferably red oxid of lead, with the 
usual and ordinary fluxes, together with sulfur-oxygen 
compound of one of the alkaline earths, preferably 
strontium; a compound of fluorin with a metal or al¬ 
kaline earth, preferably sodium; and a refractory ma¬ 
terial melting only at a very high temperature; a semi¬ 
opaque, semi-translucent glass can be manufactured 
whose general color is white or whitish and without 
“the color” or “the fire” ordinarily present in com¬ 
mercial opal glasses. 

I have found in the development of my invention 
that the use of compounds of sulfur and oxygen, with 
either calcium, strontium, barium or magnesium, when 
used in connection with the fluorin-metal, fluorin-al- 
kaline compound in said lead batch, have specific ef¬ 
fects upon the color of the resultant glass produced 
from their admixture and fusion. That when all of 
the ingredients are melted in a closed pot until com¬ 
plete fusion takes place, that the stability of the color 
or opacity and the translucency is afifected according 
to the sulfur-oxygen-strontium and the fluorin-metal 
or alkaline earth compounds used, some of which give 
better results than others. The use of some of these 
combinations of ingredients permits of greater con¬ 
trol of the batch and the resultant glass made there¬ 
from than others. These results, to a great extent, 
depend upon whether sulfur and oxygen are used with 
calcium, strontium, barium or magnesium in combina- 


102 


tion with fluorin combined with an alkaline earth or 
calcium, sodium, lead, magnesium or other metaL or 
fluorin injected into the glass batch by means of the 
mineral cryolite. The reactions of the sulfur-oxygen 
compounds are quicker with magnesium and calcium 
than with strontium and barium, whose reactions take 
place as to speed in the order named, the last being 
the slowest. The same is true with reference to the 
fluorin compounds, the reaction is quickest with cal¬ 
cium in combination with fluorin and slower with 
sodium, and with any other metal with which fluorin 
is combined which can be used for glass making pur¬ 
poses. I have found that when the melting points 
of the sulfur-oxygen and fluorin compounds most 
nearly approach the melting points of the refractory 
materials used, preferably china-clay or alumina, the 
better the resultant glass will be as to color, texture, 
fusion and working qualities when blown or pressed. 

I have also found that by the use of a sulfur-oxy¬ 
gen-strontium compound in connection with a fluorin 
metal or alkaline earth compound and a refractory ma¬ 
terial of the character of china clay or alumina, that 
the color or opacity or the translucency of the result¬ 
ant glass can be controlled to almost any desired de¬ 
gree, for the reason that when such a combination of 
ingredients is fused in connection with the ordinary 
lead batch containing the ordinary fluxes, the glass 
can be perfectly fused and kept in the melting pot for 
a longer melting period without losing its capacity, 
color and translucency (as is the case in ordinary 
semi-opaque, semi-translucent glasses), than when 
made with a lead batch and other combination of 
opacifying ingredients. 

One of the formulas which will produce a semi- 
opaque, semi-translucent glass according to my in¬ 
vention, giving the ingredients thereof by weight, is 
substantially as follows: 


103 


Sand, 100 parts; soda ash, 49 parts; red oxid of 
lead, 56 parts; feldspar, 120 parts; sodium fluorid, 
7 1/2 parts; strontium sulfate, 13/4 parts; sodium 
chlorid, 5 parts; alumina, 22 1/2 parts; niter, 5 parts; 
antimony, 1/2 part. 

Without departing from the spirit of my inven¬ 
tion, the quantities of the ingredients as above given 
may be varied; litharge may be substituted for red 
oxid of lead, with proper adjustment as to oxygen 
content; calcium fluorid may be substituted for sodium 
fluorid, but at a disadvantage as to control of spe¬ 
cific effects ; any of the alkaline earths may be sub¬ 
stituted for strontium, but at a disadvantage; cryo¬ 
lite may be substituted for sodium fluorid; any flux 
that would perform the functions of sodium chlorid, 
niter and antimony may in like manner be used with 
similar results. 

After the ingredients, as hereinbefore set forth, 
have been mixed, they are placed in a closed pot 
and heated until a complete fusion has taken place 
and when the desired color and opacity has been ob¬ 
tained, as may be ascertained by trials taken from 
time to time, the glass is taken down and worked in 
the ordinary way by blowing or pressing to produce 
the desired commercial articles therefrom. 

The preferred batch set forth heretofore weighs 
all told 367.25 pounds and contains two aluminum 
compounds, feldspar (AlKSi 3 0 8 ) and alumina 
(A1 2 0 3 ). The percentage of aluminum in these two 
compounds is respectively 9.7% and 53%, so that the 
feldspar contains 11.64 pounds of aluminum and the 
alumina contains 11.92 pounds of aluminum. The 
total weight of aluminum is therefore 23.56 pounds, 
which is 6.41% of the total batch. The fluorin in 
the batch is carried by the sodium fluorid (NaF), 
the percentage of fluorin being 45.2% or 3.39 pounds, 
which is .92% of the total batch. The 1.75 pounds 
of strontium sulfate is equal to .47% of the batch, 


104 


and the sulfur contained therein is .08% of the total 
batch, while the 5 pounds of sodium chlorid is 1.36% 
of the total batch and the chlorin contained therein is 
.82% of the total batch. The aluminum, fluorin, sul¬ 
fate and chlorid are the coloring agents and the fore¬ 
going percentages are set forth to indicate more clearly 
the relative proportions of these ingredients as com¬ 
pared with the totaL batch. 

As heretofore set forth other substances contain¬ 
ing the opacifying ingredients might be substituted if 
an adjustment is made to secure the proper quantity. 
The amount of the opacifying agents may also be 
varied between considerable limits depending upon 
the amount of color desired in the glass. 

What I claim as my invention is: 

1. A semi-opaque semi-translucent glass made by 
fusing together in a batch a substantially clear glass 
batch with aluminum, fluorin, chlorin and sulfur com¬ 
pounds. 

2. A semi-opaque, semi-translucent glass made by 
fusing together in a batch a substantially clear glass 
batch with aluminum and fluorin compounds, a sul¬ 
fate and a chlorid. 

3. A semi-opaque, semi-translucent glass made by 
fusing together in a batch a substantially clear glass 
batch with compounds containing aluminum, fluorin, 
chlorin and a sulfate, with-the aluminum in excess of 
the fluorin. 


No. 1,261,015. Glass and Method of Making It. 

Enquist. Apr. 2, 1918. 

This invention is intended to improve the strength, 
appearance and temper of glass, especially soda glass. 

To the basic glass batch a certain proportion of 
lithia and potassa-bearing minerals, as lepidolite, is 
added. This serves to agitate and mix the batch. 

I claim: 



105 


1. The method of making glass which consists in 
adding an appreciable quantity of lepidolite to a glass 
batch, and then fusing the batch thereby, to produce a 
glass in which the strength, temper and appearance 
thereof is increased. 


No. 1,271,652. Method of Making Colored Glass. 

Bellamy. (Assigned to Western Electric Co.) 
July 9, 1918. 

This invention relates to a method of making colored; 
glass, and more particularly to the manufacture of 
ruby colored glass in which in the best known and com¬ 
monest used processes gold is used for coloring ma¬ 
terial. 

The principal object of this invention is to cheapen 
the process without deterioration of the product, by 
means of a reduction in the amount of gold required 
to satisfactorily color a given glass forming batch. 

In accordance with the general features of this in¬ 
vention, the amount of gold required to satisfactorily 
color a given glass forming batch is reduced to a mini¬ 
mum by the introduction into the batch of tin oxid and 
a subsequent specific heat treatment of the batch. 

The specific combination of the constituents of the 
glass forming batch hereinafter set forth is also be¬ 
lieved to be novel. 

The invention as hereinafter described may be readi¬ 
ly utilized for producing glass of substantially any 
color, but is especially beneficial in the production of 
ruby colored glass. The introduction of the tin oxid 
into the glass batch serves to decrease the amount of 
coloring matter necessary to obtain a desired depth of 
color in the glass. As the more satisfactory forms of 
ruby colored glass are colored by the addition of gold, 
the reduction in the amount of this coloring matter 
for the production of ruby glass results in a marked 
economy, and consequently this invention is of a maxi¬ 
mum benefit in the production of ruby glass. 



106 


The following description will consequently be con¬ 
fined to the method utilized for the production of ruby 
colored glass, but obviously the invention is not lim¬ 
ited to the production of ruby colored glass, but is ap¬ 
plicable to the production of all types of colored glass 
in which tin oxid is used in connection with the glass 
forming silicates, as hereinafter described. 

The term ruby glass is applied to red glass colored 
by the use of copper, gold, selenium, and, in some cases, 
flowers of sulfur, the color of the glass varying very 
considerably in intensity and shade. The best ruby 
colored glass is obtained by the use of gold, the other 
substances enumerated above producing a glass having 
a color which is so dense that if the glass is of any 
material thickness, very little if any light will pene¬ 
trate through it. For this reason the gold process is 
almost universally used when ruby glass having the 
required depth and uniformity of color is desired, and 
in the following description the invention will be ap¬ 
plied to the production of colored glass by means of 
the gold process. 

Generally speaking, glass consists of a mixture of 
two or more silicates united by fusion into a homo¬ 
geneous, hard, brittle mass. Silica or sand usually pre¬ 
dominates combined with the bases potash, soda, lime, 
lead, etc. Oxide and other materials are frequently 
used as auxiliaries to impart colors or otherwise alter 
the physical properties of the glass. There are eight 
classes of glass silicates in which silica is combined 
with some or all of the above-mentioned bases. A 
silicate of sodium or potassium containing a large per¬ 
centage of lead is known as strass. This particular 
type of glass varies from colorless glass to a slightly 
straw colored glass if the percentage of lead is high, 
said color being due to the lead silicate. Strass glass 
is the only kind of glass which can be combined with 
gold to produce a ruby color. Glass made in accord- 


107 


ance with this invention consists of a glass batch con¬ 
taining the following ingredients given in percentage 
by weight: 


Sand 

36.30 

Red lead 

36.30 

Nitrate of soda 

16.00 

Oxid of antimony 

1.70 

Borax 

1.70 

Oxid of tin 

3.075 

Potash 

4.60 

Lime 

0.30 

Gold (10 K) 

0.025 


These percentages, may be slightly varied and satisfac¬ 
tory results obtained, although the preferred percen- 
ages above enumerated give the most satisfactory deep 
ruby transparent color. Gold is added to this glass 
batch as gold chlorid. This gold is added to the batch 
by dissolving 10 carat gold in aqua regia, which solu¬ 
tion is stirred into the silica or sand, and in this way 
the gold chlorid is intimately incorporated in the batch. 

The sand, red lead, nitrate of soda, oxid of anti¬ 
mony, borax, oxid of tin, potash, lime, and gold, which 
comprise the batch are then placed in a pot and heated 
to a very high temperature, about 2,400 degrees Fah¬ 
renheit, which causes them to undergo a violent chemi¬ 
cal reaction. This chemical reaction results in the 
forming of complex silicates and the liberation of gases 
not needed in the compounds. When the chemical re¬ 
action has been completed and the evolved gases ex¬ 
pelled from the hot solution transparent, viscous glass 
is formed. This transparent, viscous glass is strass 
glass holding in suspension gold and tin which have 
the potentiality of giving to said glass the ruby color 
if properly treated as hereinafter described. During 
the chemical reaction the gold chloride has been disso¬ 
ciated, leaving finely divided gold distributed through- 


108 


out the glass. A sample of the hot glass gathered 
from the pot at this stage of the operation is the color 
of strass glass, varying from a colorless to a slightly 
straw color. This glass is then allowed to cool, after 
which it is reheated to plasticity, at which time the 
color, due to the gold, develops, varying in intensity 
from a rose color to a dark ruby, depending upon the 
amount of gold present. 

Various theories have been advanced to explain why 
finely divided gold homogeneously dissolved in glass 
assumes a ruby color under certain conditions. Ultra- 
microscopic tests show that on reheating the gold is 
converted into the collodial form of red gold hydrosol. 
Another theory is that on cooling glass quickly the 
gold separates out in particles of the magnitude of 
amicrons which are too small to reflect light and which 
by reheating, until the glass becomes soft, grow until 
they attain the size of ultra-microns which reflect the 
ruby color. As the ruby color is light reflected by 
particles of gold, the depth of color depends upon the 
amount of gold dissolved. In the well-known method 
of making ruby glass without the use of tin oxid one 
ounce of gold will produce the proper ruby color in 
sixty pounds of glass, the glass without the gold being 
transparent and reflecting no light. By reducing the 
transparency of the glass it was discovered that less 
gold would be needed, and the transparency of the 
glass was most efficiently and satisfactorily reduced 
by the addition of oxid of tin. A general law that a 
reduction in the transparency of the glass will reduce 
the amount of coloring matter required to color the 
glass any particular color desired seems to be substan¬ 
tiated by the experiments which have been conducted 
in connection with ruby, green and other colors. The 
oxid of tin added to the batch remains in suspension 
in the glass, producing opalescence, that is, the glass 
has a frosty straw colored appearance, and this opales- 


109 


cence assists in the reflection of the ruby color by the 
particles of gold to such an extent that one-fifth of the 
original amount of gold above referred to, with the 
proper amount of tin oxid added, gives the desired 
depth of ruby color. The tin oxid in addition to reduc¬ 
ing the quantity of gold required also materially in¬ 
creases the strength and reduces the brittleness of the 
glass, which eliminates the usual annealing operation 
which is regularly performed on glass, the glass con¬ 
taining the tin oxid having a toughness equal to that 
of the ordinary run of glass which has been annealed. 

Further, since the quantity of gold necessary to be 
carried in suspension to obtain the necessary depth of 
color is greatly decreased, the tendency of the glass 
to vary in color from the top to the bottom of the mix¬ 
ing and heating pot is very much lessened. The small 
amount of gold used in the improved process results 
in a more equalized distribution thereof through the 
mass of glass in the pot during the melting operation, 
said amount of gold being so minute that it has very 
little tendency to settle in the bottom of the pot. With 
larger quantities of gold, since the specific gravity of 
the gold is considerably greater than the mass of the 
batch, the gold tends to settle in the bottom of the 
pot and an unequal distribution of color through the 
mass in the pot results. 

This equal distribution of the gold through the mass 
in the new process in which tin oxid is used permits of 
the successful manufacture of very small quantities 
of ruby glass. Quantities as small as ten pounds have 
been successfully made in which the glass has a very 
uniform color; whereas in the old process, in which the 
tin oxid is not used, satisfactory ruby glass could not 
be made in batches of less than 200 to 300 pounds. 
The improved process of making glass as hereinbefore 
described therefore results in a more economical pro¬ 
duction of a much better glass which has a greater uni¬ 
formity of color. 


110 


Obviously this invention is not limited to the pre¬ 
ferred method or article hereinbefore described, but 
is applicable to the production of all colors of glass, 
the production of which is included within the spirit 
and scope of the invention, as set forth in the appended 
claims: 

Claims: 

1. The process of making ruby colored glass, which 
consists in mixing a glass forming batch containing tin 
and gold with the usual glass forming silicates, heating 
said batch to substantially 2,400 degrees Fahrenheit, 
cooling said batch, and finally reheating it to plasticity. 

2. The hereinbefore described process of making 
ruby colored glass, which consisted in combining sand, 
red lead, nitrate of soda, oxid of antimony, borax, oxid 
of tin, potash, lime and gold in proportions substan¬ 
tially as hereinbefore described. 


No. 1,277,493. Manufacture of Glass. Sherwood. 
Sept. 3, 1918. 

Niter cake, sodium hydrogen sulfate, is a by-product 
in the manufacture of nitric acid and its use in the arts 
is extremely limited, so that it is plentiful and is, in 
effect, a waste product. 

The principal object of the present invention is to 
provide for industrially using niter cake, thereby con¬ 
verting this by-product, heretofore largely wasted, into 
a valuable raw material. 

To this and other ends hereinafter set forth, the in¬ 
vention, stated in general terms, comprises the im¬ 
provement in the manufacture of glass which con¬ 
sists in making glass with nitre cake as a fluxing or 
alkali component thereof, and my invention is based 
upon the discovery that this can be done by the con¬ 
joint use of carbon or carbonaceous matter and nitre 
cake in the batch or mixture from which the glass is 
made. 



Ill 


The production of glass by the use of nitre cake does 
not by any means simply involve the substitution of 
niter cake for fluxing components such as soda ash, 
sodium carbonate, or salt cake, sodium sulfate, for it 
is impossible to commercially make glass with nitre 
cake unless an appropriate amount of carbon is added 
to the mixture or batch from which the glass is made. 
Good results have been obtained by the use of carbon 
or carbonaceous matter in the form of pulverized bi¬ 
tuminous coal. I have produced successful glass by 
the use of the following proportions in the batch or 
mixture; sand 45 per cent; niter cake 43.4 per cent; 
calcium oxid 6.4 per cent; and pulverized bituminous 
coal 5.2 per cent, but the invention is not limited to 
these proportions nor ingredients, since the point is 
that niter cake can be used in the batch or mix provided 
an appropriate proportion of carbon is present, which, 
generally speaking, is twice as much carbon as is used 
with normal sulfate to produce the same quality of 
glass in each case. From the proportions above given 
it appears that the amount of carbon is substantially 
twice what it would be in the case of the use of normal 
sulfate. I may say that, if desired, nitre cake and 
carbon can be used in association with other sodium 
components such as soda ash or salt cake. In accord¬ 
ance with custom any imperfections of color that may 
occur in the glass can be corrected in ways that are well 
understood by those skilled in the art. 

I claim: 

1. In the manufacture of glass a batch or mix con¬ 
taining niter cake and carbon amounting at least to 
11% of the niter cake. 

2. In the manufacture of glass a batch or mix con¬ 
taining niter cake and substantially twice as much car¬ 
bon as is appropriate for normal sulfate. 


112 


British Patents. 

1470 of 1855 to Margueritte. 

Materials : Relates to the production of metallic 
silicates for the manufacture of glass and crystal. 
Silicate of lead, zinc, etc., prepared by heating the cor¬ 
responding oxide with silica—is calcined with chloride 
of potassium, sodium, barium or calcium. A volatile 
metallic chloride is formed and may be condensed and 
then boiled with carbonate of lime, so as to form a - 
metallic carbonate from which the silicate may be 
again prepared. A frit or residue is left after the ex¬ 
pulsion of the volatile chlorides, and may be used for 
making glass. Glass and crystal may also be pre¬ 
pared by calcining suitable proportions of salt, silica 
and lime with kaolin or other clay. The hydro¬ 
chloric acid evolved during the reaction may be col¬ 
lected and utilized. 


1715 of 1855 to Paris. 

Obtaining metal: Sulphate of lead is employed as 
a substitute, in whole or in part, for minium (red 
lead), in the manufacture of crystal, glass, enamel, 
or other vitreous products, the sulphates being con¬ 
verted to the oxide by charcoal or other reducing agent, 
during the manufacture of the frit, etc. 


2371 of 1855 to Richardson. 

Materials: Relates to the use of purified native 
borate of lime, either alone or fritted with soda in the 
form of carbonate as a substitute for borax in the 
manufacture of glass. The native mineral is levigated 
and a jet of steam is admitted into the dolly tub to 
promote the purification. Sand and other coarse im¬ 
purities are separated in the dolly, and the finely di¬ 
vided borate flows on through spouts into settling 
tanks. The soluble impurities may be siphoned off. 
The purified borate may be dried at a gentle heat, being 




113 


occasionally agitated by the workman. For common 
glass it is sufficient to brush off the sand, etc., from 
the masses of mineral, or to expose them to a current 
of water. For pale glass, suitable for medicine bot¬ 
tles, etc., the crude borate may be used. A modification 
is described in which sulphate of soda is used instead 
of the carbonate. 


2537 of 1855 to Margueritte. 

Materials: Relates to the manufacture of glass, 
crystal, enamels, glazings and like vitreous composi¬ 
tions. Suitable proportions of the materials employed 
are given in the specification. A transparent glass, 
free from potash and soda, is obtained by calcining a 
mixture of silica, lime and alumina. Instead of em¬ 
ploying pure materials a clay may be used, to which 
pure materials may be added as required, to obtain 
the desired relative proportions. It is stated that by 
this method with a clay of specified composition, a 
green-tinted glass is obtained, which might be used for 
making bottles, and that kaolin might be used for win¬ 
dow glass, looking glass, etc. For making crystal, 
without potash, a mixture of silica, oxide of lead, lime 
and alumina is employed, the lime being substituted 
for the potash ordinarily used. Oxides of lead or 
zinc, etc., may also be added to this mixture. Felspar 
which contains potash or soda, or both these alkalies, 
is also employed for the manufacture of glass, the pro¬ 
portion of alumina being reduced, if necessary, by the 
addition of silica and lime. The proportion of alkali 
may be increased, if desired. To produce a vitreous 
product which may be used for the manufacture of 
crystal, the felspar may be calcined with metallic ox¬ 
ides, such as oxide of lead, the proportion of silica 
being increased by the addition of sand, etc. The ad¬ 
dition of the other oxides, such as oxides of zinc or 
bismuth, produce a vitreous fusible, translucent ma- 



114 


terial. Other oxides may be added to tint the result¬ 
ing product. Vitreous compounds are also obtained 
from phosphates, chiefly phosphate of lime, although 
biphosphates of potash, soda, baryta, strontia, mag¬ 
nesia, alumina, lead, zinc, cobalt and etc., may be used. 
The biphosphate may be vitrified alone, or in combina¬ 
tion with alumina, silica, kaolin, clays, felspar, etc. 
The biphosphate of lime in such combination is stated 
to decompose salts and acids or other elements which 
can be volatilized, while it also serves as a decoloriz¬ 
ing agent for contained iron. By employing biphos¬ 
phate of lime, cheap substitutes for minium may be 
used, e. g., sulphate of lead or zinc, and the arsenio- 
sulphfdes of /cobalt ,and nickel, sand other natural 
minerals may be substituted for artificial oxides. 
Tinted products, suitable for coating colorless crystal, 
or as enamels, are obtained by the addition of the ox¬ 
ides of cobalt, chromium, copper, uranium, etc. 


242 of 1856 to Chance. 

Materials: Moulding, firing. Articles are moulded 
from pulverized vitreous matter, such as cullet or waste 
glass, with or without the addition of sand or other 
suitable material. The pulverized material is mixed 
with water to enable it to hold together, and it is then 
pressed into a mould of the required shape. When re¬ 
leased from the mould the moulded article is carefully 
dried in a suitable kiln at a low temperature, and, 
when dry, is immersed in and covered over with sand, 
to regulate the heat and to support any parts, which 
might give way during burning. The temperature of 
the kiln is then raised gradually, until the material is 
partially fused or agglomerated into a compact mass. 

1204 of 1856 to Medlock. 

Materials: Glass enamels and the other vitrified 
substances are made by fusing a clay containing from 
two to ten per cent of potash or soda, with such a pro- 




115 


portion of sand and lime, or carbonate of lime, as will 
produce with the constituents of clay, the definite 
chemical compounds known as double silicate. For the 
purpose of reducing contained iron to the lowest oxide, 
and so improving the color of the product, black mar¬ 
ble, the color ofi which is produced by carbon, is sub¬ 
stituted for the lime or carbonate of lime. Metallic 
oxide of the ores may. be added to produce the required 
color and opacity of enamels, etc. 


1515 of 1856 to Johnson. 

Materials: Consists in using barium carbonate, ob¬ 
tained by decomposing barium sulphide in aqueous 
solution with carbon dioxide in the presence of potash, 
soda or other alkali, in the manufacture of glass and 
crystal, the compound partially or wholly replacing 
sodium or potassium carbonates in the production of 
silicates. 


1813 of 1856 to Chamblant. 

Obtaining Metal: Molten glass is mixed and treated 
by forcing air or gas through it whilst in the melting 
pot, by means of a platinum tube, fitted with a rose 
and connected by a flexible tube with a compression 
pump. When air is used it causes the oxidation of 
excess of carbon and etc., whilst hydrogen, carbonic 
oxide and etc. cause the reduction of sulphates, phos¬ 
phates and other substances. Steam may be used to 
decompose or volatilize chlorides present in the glass 
in injurious proportions. 

595 of 1857 to Brooman. 

Chaining Metal: Consists in making a sodium sul¬ 
phate for use in the manufacture of glass, by treating 
sodium chloride, either in solution or placed in the 
flues of a furnace, with sulphurous acid; or, the sul¬ 
phurous acid may be passed into a solution of sea 
salt. Sodium sulphite and hyposulphites are formed 
at the same time. 





116 


1197 of 1858 Bower. 

Obtaining Metal: Powdered sulphate of barytes, 
silica or fine sand, and muriate of soda are calcined 
together at a strong red heat, until they become a dry 
powder. The compound thus formed, with the addi¬ 
tion of the proper proportion of lime, is then con¬ 
verted into glass. If the glass is required to be color¬ 
less, the sulphate of barytes and sand are first purified 
with acid. 


1129 of 1860 to Newton. 

Materials: Oxide of zinc, used in combination 
with oxide of nickel, which acts as a decolorizing 
agent, is substituted for oxide of lead in the manu¬ 
facture of flint glass, and is mixed in various propor¬ 
tions with silica and alkali to form the “batch” in the 
usual manner. 


1732 of 1861 to Cobley. 

Materials: Relates to the preparation of lead and 
barium silicofluorides which, with the corresponding 
silicates, may be used either conjointly or separately as 
enamels, glazes or pigments, in the manufacture of 
glass. Hydrofluosilic a did prepared by heating a 
mixture of finely ground fluospar and powdered sand, 
glass, flint, infusorial earth, slag or any native silicated 
base with sulphuric or other acid, is passed as gas into 
a solution of lead or barium salts containing hydro¬ 
chloric, acetic or creosotic acid, or, the liquid acid is 
simply mixed with the metallic solution. The precipi¬ 
tate is either used in the state of pulp or is dried. Al¬ 
ternatively, the acid may saturate, oxides of lead or 
barium hydrate or qarbonate, with or without boiling. 
Lead silicofluoride is also obtained by acting upon a 
lead silicate or a mixture of lead or slag or silica with 
liquid hydrofluoric acid; or, the acid gas may be passed 
into a condenser containing the finely powdered ma¬ 
terials. 




117 


1005 of 1862 to Cobley and Wright. 

Materials: The finely divided silicious residue from 
the metallurgical treatment of gold and silver ores is 
washed and used as a substitute for flint in the manu¬ 
facture of glass. 


2050 of 1862 to Gossage. 

Materials: Sodium or potassium silicate for use in 
glass making is obtained by passing a mixture of fur¬ 
nace gases, air and steam, over solid sodium or potas¬ 
sium chloride, thereby volatilizing it, and then passing 
the mixed vapors through a granular mass or natural 
substance, such as flint nodules, granite or felspar, 
which contains silicon. This mass has previously 
been intensely heated by the passage of furnace gases 
mixed with air through it, and in'consequence decom¬ 
position ensues, fluid silicate being dawn off from the 
furnace. 


2187 of 1862 to Webb. 

Materials: In obtaining metal for flint glass, sul¬ 
phate or chloride of potassium is used in place of, or in 
combination, with the carbonate usually employed. 
In carrying out the process potassium sulphate, for 
example, mixed with sand or the like is fused, cooled, 
mixed with sand and metallic oxides and again fused. 
The first fusion may be facilitated by the addition of 
carbonaceous matters. 


3080 of 1862 to Whitburn. 

Obtaining Metal: English sand is purified for glass 
making purposes, by calcining or roasting it in open 
air stoves or ovens, which may be heated by the waste 
gases of furnaces, coke ovens, etc. 

878 of 1863 to Brooman. 

Materials: In a process for obtaining barium ox¬ 
ides, a mixture is obtained containing zinc oxide and 
barium carbonate, which may be used in glass making. 

- " 







118 


5 of 1865 to Parker and Tanner. 

Materials : A residue left in a retort when prepar¬ 
ing oxygen, and consisting of a mixture of caustic 
soda and lime, may be used in glass making. 


897 of 1865 to Baugh: 

Stained glass: Manganese oxide is added to the 
materials used in making glass for lamps and other 
reflectors, in order to give the glass a purple color. 
White arsenic or arsenious acid may also be added 
to give opacity. Platinum chloride solution is applied 
to the glass, which is heated in a muffie. 


12220 of 1865 to Emerson and Fowler. 

Obtaining Metal: Alkaline, earthy, or common 
metal oxides are fused with silicas, to form glass, and 
any well-known coloring materials may be added dur¬ 
ing the fusion. The materials are heated by a blast of 
air under pressure, which is gradually raised in tem¬ 
perature up to that of hot blasts used in blast furnaces 
for iron smelting. Metal obtained by remelting soda 
water bottles, etc., is used for casting mantlepieces, 
sinks, wash hand basins, monumental and other tab¬ 
lets, slabs, coffins, boxes, and other hollow articles and 
the linings for hollow articles. 


1905 of 1865 to Chaudet. 

Stained glass: Glass is colored by means of 
chromium oxide. 


200 of 1866 to Penney. 

Materials : The ash resulting from the combustion 
of hoghead, cannel, and similar coals, shale, and the 
like, or the constituents of this ash, after treatment 
with acids, or the refuse silica from china clay, or other 
similar material, is used for making glass. 






119 


983 of 1866 to Johnson. 

Obtaining Metal: White or semitransparent glass 
similar to enamel, milk, opal or alabaster glass, is made 
in the usual way from a mixture of the following 
ingredients: Double fluoride of aluminium and sodi¬ 
um, pearlash or soda, sand, chalk, saltpetre, and oxide 
of manganese. 


2026 of 1866 to Newton. 

Materials: Consists in making insoluble potassium 
or sodium silicates for the manufacture of glass by 
fusing together sand and the corresponding metallic 
nitrate or sulphate. 


2593 of 1866 to Bousfield. 

Materials: Manganese dioxide, as well as a mixture 
of oxide and sulphate of manganese, which have been 
recovered from chlorine still liquors and other solu¬ 
tions containing manganese, are employed in the manu¬ 
facture of glass. The said liquors are treated with 
alkali waste, producing manganese sulphide, either 
alone or mixed with sulphur, and on roasting this pre¬ 
cipitate, a residue containing oxide and sulphate of 
manganese is left. The residue, when heated with 
sodium nitrate in closed vessels, yields a mixture of 
manganese dioxide and sodium sulphate, which are 
separated by lixiviation with water. 

133 of 1867 to Weldon. 

Materials for making glass. An artificial peroxide 
of manganese, containing over 55 per cent of dioxide 
and useful for glass manufacture, is made by injecting 
air into a mixture of a lower oxide of manganese and 
water. The air may be heated. 





120 


2114 of 1867 to Hargreaves. 

Materials : Steel slag or the steel cinder obtained 
in making steel, etc., by the process described in the 
British Patent No. 2046, of 1867, is used in the manu¬ 
facture of glass by fusing it with silica, lime and lead 
or zinc oxides or other glass making materials. 


1854 of 1868 to Elsdon and Stein. 

Materials; moulding: Glass making material con¬ 
sisting of silicious material and lime or other flux, or 
of materials which fuse into glass, is mixed with fuel 
and smelted in a blast cupola or other suitable furnace. 
Gaseous, instead of solid fuel may be used. The melted 
glass is run into moulds, to produce paving slabs, etc. 
A portable furnace may be used, the glass being run 
directly from it into trenches to form foundations for 
houses, or run between mould plates to form walls. 

1920 of 1868 to Fleury. 

Materials: A soluble silicon hydrate, made by heat¬ 
ing silica or silicious materials in presence of sulphur 
and decomposing the resulting sulphides of silicon by 
water, is used in the manufacture of glass, 

1972 of 1868 to Clark. 

Kaolin, sand, grit, metallic oxides, and other ma¬ 
terial used for making glass are freed from iron oxides 
or other iron compounds by heating them to a red heat 
with ammonium chloride, or ammonia, or a material 
containing ammonia. The various vessels used are 
similarly treated, to free them from iron. By adopting 
this process of purification soda compounds may be 
used instead of potash, without producing a green 
color in the glass. 

2277 of 1868 to Green. 

Materials: Granular or talcose quartz, i. e., quartz 
containing steatite or talc, is used as an ingredient in 
making flint glass. 






121 


3101 of 1868 to Archereau. 

Obtaining metal: An intense heat for chemical, 
metallurgical and other purposes is obtained by burn¬ 
ing a mixture of a combustible gas, such as carbonic 
oxide or hydrogen and a gaseous supporter of com¬ 
bustion, under a high pressure. Gases may be pumped 
along separate pipes into a mixing tube and then 
through perforations in the base of a crucible in which 
they are burned. This method may be applied for the 
manufacture of glass by heating in the crucible a mix¬ 
ture of potassium or sodium sulphate, silica and lime. 
Sulphurous acid and oxygen are given off, and the resi¬ 
due consists of glass. 


3786 of 1868 to Prince. 

Materials: Relates to the manufacture of a silicious 
material for the various purposes. Quartz or flint is 
powdered and mixed with gas-tar, petroleum or other 
carbonaceous substances or hydrocarbon. The mix¬ 
ture is moulded into small balls and heated in a cruci¬ 
ble in a current of sulphur vapor, carbon bisulphide, or 
sulphuretted hydrogen. Silicon sulphide is thus ob¬ 
tained as a greyish-white powder which is decomposed 
by water, forming a solution of soluble silica and sul¬ 
phuretted hydrogen. The sulphuretted hydrogen may 
be collected and used again and the solution of silica 
may be used as a material in the manufacture of 
glass. 


2284 of 1870 to Balmain. 

Materials: Caustic soda and potash are used in 
place of carbonates of those materials. They are 
mixed in the manner usual with the carbonates, or 
they are mixed roughly, the mixture being fritted and 
reground, or the alkali is previously fritted, melted or 
otherwise combined, with a portion of the ingredients, 
and the products subsequently mixed with the re¬ 
mainder. 




122 


1291 of 1871 to Richardson. 

Materials for lenses for signal lamps. The glass is 
formed of 140 parts of sand, 10 of lime, 20 of fluor¬ 
spar and 60 of soda ash, with one of coal or coke dust 
as a coloring material; or, instead of carbon, iron and 
manganese may be used. The peculiar color pro¬ 
duced may afterwards be changed into a more perfect 
ruby by staining. 

1772 of 1871 to Wilson. 

Stained glass; moulding, pressing: Tinted or col¬ 
ored lenses for spectacles or eyeglasses are made of uni¬ 
form tint for different thicknesses by graduating the 
alloy or coloring matter, and are made to appear color¬ 
less to the wearer. Lighter and darker pink tints are 
obtained by mixing in various proportions white opti¬ 
cal glass “manganese,” and “ chromium.” The com¬ 
position is cast in a mould, annealed, reheated and 
flattened endwise by pressure, and annealed again, and 
is ready to be worked into lenses. The method of 
pressing brings the grain into a position rendering 
the glass apparently colorless to the wearer. 


328 of 1873 to Smith. 

Materials : Pure barium carbonate may be used, 
instead of oxide of lead, for making crystal. 

3750 of 1873 to Britten. 

Materials. Obtaining metal: Relates to the manu¬ 
facture of glass for bottles, slabs, sheets, tiles, utensils, 
etc., from slag. The slag from the smelting of iron or 
other ores is mixed in the fused addition with sand, 
cullet, soda, potash or metallic oxides, the proportions 
varying with the quality and color of the glass re¬ 
quired. To remove carbonaceous and other impuri¬ 
ties, arsenic or mineral oxide may be employed and 
lead oxide, zinc oxide or barium oxide is used to facili- 






123 


tate the manipulation. Sodium sulphate mixed with 
ground coke or charcoal may also be added. The 
materials may be introduced in the form of powder or 
in the fused state, and the molten mass is either further 
heated in a stationary furnace, or run into vessels 
which may be lined with nonconducting materials, 
provided with furnaces and mounted on cylinders for 
conveying the metal to the glass works. 

3007 of 1874 to Deane. 

Materials: To manufacture artificial marble, lead 
oxide, sand, pearl ash, nitre, borax, white arsenic, andi 
cryolite are mixed together and fused in a pot. The 
molten mass is then rolled upon an iron table and the 
slab produced is annealed in a furnace and may be 
afterwards ground and polished. The fused composi¬ 
tion may be moulded in iron moulds. 


91 of 1875 to Mackay. 

Materials: Spent bleach, soda lime, gas lime, tan¬ 
ner’s lime, soap lime, and other waste lime products 
are mixed together with coal dust and waste alkaline 
liquors from paper, etc., works. The mixture is cal¬ 
cined in a kiln and then used in the manufacture of 
glass. 

Sawdust, spent bark, etc., may be used instead of 
coal dust, and in some cases the addition of alkaline 
liquor is dispensed with. 

175 of 1875 to Vera. 

Obtaining metal: A soluble glass made of sand, 
carbonate of potash and carbon is employed for elec¬ 
tric insulation. 


2669 of 1875. Heinzerling. 

Materials: Residues obtained in the manufacture of 
potassium bichromate, iodine and bromine are used 






124 


for making common bottle glass. The residues con¬ 
tain ferric oxide, alkaline silicates, calcium sulphate, 
lime, magnesia, etc. 


4017 of 1875 to Britten. 

Obtaining metal: Glass is obtained from flint 
stones, quartz fragments, sand stone, or other suitable 
mineral, instead of from the sand or comminuted silica 
commonly used by heating a pile of the silicious stones 
in a suitable tank and introducing a more or less con¬ 
tinuous supply of the fluxing ingredients. The tank is 
preferably made with a floor sloping down to a well, 
in which the glass collects as it runs from the stones. 


2519 of 1876 to Johnson. 

Obtaining Metal: When commercial nickel is melt¬ 
ed with copper or other metal to form an alloy the 
composition of the fluxes employed is the same as the 
composition of bottle glass. The vitreous scoria ob¬ 
tained is pulverized in order to remove the grains of 
nickel by means of a magnet, and is afterwards melted 
in an ordinary glassmaker’s crucible to manufacture 
bottle glass, 

2950 of 1876 to Wallace. 

Materials: Barium carbonate, obtained free from 
iron by a special process is stated to be applicable for 
the manufacture of cheap flint glass. 

1701 of 1877 to Robbins. 

A translucent material is formed of “pure silicate, 
silicate of soda or other silicate, as silicate precipitate, 
silica and silica precipitate, silex, quartz, glass, flux, 
felspar, lustres, etc., with paraffin, benzoline, liquid and 
crystalline, and also with the oxides as magnesite or 
zinc baryta, or the sulphates, carbonates, and other 
limes.” These or other ingredients are mixed, ground, 
gauged and indurated as a cement with heat or chemi- 






125 


cals, and fired to flux or melt as enamels, lustres, glass, 
etc. The materials are treated with benzoline, paraffin, 
and other oils, which when heated throw off vapors 
from one or more furnaces, chambers, heating or 
other apparatus to pass into other chambers wherein 
the said fumes become condensed and fixed as ma¬ 
terial, otherwise formed into compounds of various 
kinds of enamels, glasses, lustres, fluxes, or other 
binders with which any downfall or other dust process 
or decoration may be employed. The material 
may be used for all purposes to which glass is 
applicable, as for lamps, shades, reflectors, ventilators, 
etc., also to' form a double decorated surface with one 
or more patterns. 

2527 of 1877 to Kew. 

Obtaining Metal: Specially applicable for telegraph 
insulators. Each of the raw materials to be used is 
fired separately; they are then all ground and mixed 
together and again fired after which they are again 
ground. The materials thus treated may be used for 
the manufacture of telegraph insulators and other ar¬ 
ticles, either by subjecting to pressure, casting in 
moulds in a liquid state, or by throwing and turning; 
or, they may be fused in a glass furnace and blown 
into the required forms. Where only one material 
such as felspar, is used, the second firing may be dis¬ 
pensed with. 


3280 of 1877 to Webb. 

Iridescent glass producing: The glass articles are ; 
exposed, while in the nearly molten state after blow¬ 
ing, and before annealing, to the fumes generated by 
placing chloride of lime, alone or mixed with the ni¬ 
trates of barium and strontium upon a hot plate or 
spoon. During this process the articles are placed in. 
a muffle in which the fumes are introduced. The 
claim includes tin and other metallic salts, or their 
equivalent chemical compound. 



126 


4505 of 1877 to Wittman. 

Iridescent glass is prepared by boiling glass in 
muriatic acid under great pressure and is employed for 
inlaying and decorating 'furniture, picture and mirror 
frames, albums, table ornaments, etc., whether of 
wood, glass, porcelain, leather or other material. 


459 of 1878 to Wirth. 

Materials for making: Slag from blast furnaces is 
used as one of the raw materials. If solid it is pul¬ 
verized by mechanical means; if hot, it is granulated 
by chilling with cold water, and afterwards dried. It 
may be used in a melted state as it comes from the fur¬ 
nace and placed in the melting pot in alternate layers 
with the other materials. The coloring due to oxides 
of iron or manganese can be destroyed if desired, by 
calcining the crushed or granulated slag. 


2156 of 1878 to' Sowerby. 

Glass of a yellow opaque tint is made by adding 
uranium and cryolite to the ordinary constituents of 
flint glass, such as a mixture of sand, soda, barium 
carbonate, nitrate of soda, and manganese dioxide. 


3403 of 1878 to Fleming. 

Materials for making: A mixture of sand or silica, 
17 parts; carbonate of soda,- 4 parts; carbonate of 
baryta, 6 parts; borax, 2 parts; produces glass equal in 
clearness and brilliancy to' the best flint glass. 


3476 of 1878 to Lake. 

Imitating marble: Material used is glass and the ar¬ 
ticles are cast in moulds or blown into the required 
form' The surface is then subjected to the action of 
the acids, or the sand blast, or ground to produce the 
desired effect. The veined and mottled markings are 
produced by adding coloring materials in the process 
of manufacture, the coloring matters being generally 






127 


metallic oxides. To imitate white or statuary marble 
an opaque glass is made from two parts of silica free 
from iron, 1 part of soda, and 3-7 per cent phosphate 
of lime; or a mixture of ten parts sand, 4 parts cryo¬ 
lite, and 1 part oxide of zinc may be used. The 
opaque black glass to imitate Belgian black marble is 
made of flint batch 600 parts, manganese 12 parts, 
oxides of iron 7_part&, zaffre 1/4 part. The invention 
is stated to be applicable to the manufacture of stat¬ 
ues, medallions, statuettes, busts, urns, vases, and 
other works of art; cornices, brackets, balusters, bal¬ 
ustrades, centre pieces, mouldings, pedestals, columns, 
altars, monuments, fountains, panels, mantelpieces,, 
table and washstand slabs, wainscoting, ornamental 
tiling and caskets. 


3727 of 1878 to Kempner. 

Milk-tinted glass: In producing milky, alabaster¬ 
like, or milk colored glass, mixtures of felspar or 
felspar-like substances, fluor spar and heavy spar, or 
witherite, soda, potash and sand are used as substitutes 
for cryolite, tin oxide, and phosphate of lime. 


4079 of 1878 to Pulvermacher. 

Translucent medium for reflecting, refracting, and 
diffusing light. Consists in coating the interior sur¬ 
face of the glass, crystal, mica, or other material used 
with a layer of fine metal, preferably platinum, by 
chemical disposition and subsequent solidification. 
The application to globes, shades and reflectors for use 
with gas, electric or other lights, is mentioned while 
the provisional specification also states that glass so 
treated may be used for the windows of cabs and other 
transparent mirrors in partitions. 


4880 of 1878 to Clark. 

Metallizing glassware: 

A reducing gas, such as hydrogen or coal gas is 
employed in blowing the glass and by its action on the 





v 

\ 

128 

metallic oxides or salts contained in the glass reduces 
them to a metallic state on the interior surfaces. Thus 
when oxide of copper is used a golden or bronzed 
aspect is obtained from the reduced copper. Besides 
glass articles generally the following applications are 
specially mentioned: Stained window glass, glass 
plaques or tiles, reflectors, lighthouse lenses and glass 
for lighting apparatus generally. 

4881 of 1878 to Clark. 

“Metallized crackle” producing: A layer of glass 
containing an easily reducible compound such as oxide 
of copper, is placed between two other layers of glass. 
When the glass is partly blown it is dipped in water 
to crackle the surface. The blowing is then finished, 
when the middle layer of glass will project through 
the expanded cracks. These projecting veins are then 
metallized by exposing the article to a reducing gas 
such as hydrogen, carbonic oxide, or carburreted hy¬ 
drogen. Successive layers of glass may be crackled 
and metallized in this way in different colors. Or the 
crackle may be made of granulated glass and the veins 
metallized as above. The ground only or both ground 
and veins may be metallized. By using clay masks 
portions only of the surface may be crackled. Vases, 
etc., in this way may have their interior surfaces met- 
talized according to the invention described in British 
Patent No. 4880 of 1878. 


53 of 1880 to Lake. 

Obtaining Metal: 

Calcium phosphate is substituted for its equivalent 
of lime in the ingredients used in making glass. The 
pot in which the materials are melted has in its cover 
a pipe of non-oxidizable metal, connected to a lead 
tube leading into water. “A narrow tube placed near 
the orifice of the crucible allows of the precipitation 
of the gases at the beginning of the operation by 




129 


throwing a small jet of water which is immediately 
vaporized.” Hydrogen phosphide and phosphoric acid 
(the latter carried off by silicic acid of the sand) pass 
over on continuing the operation for a specified time, 
and form an acid liquor in the condenser, which may 
serve for repeated condensations, or be at once con¬ 
centrated. 


2342 of 1880 to Morgan-Brown. 

Obtaining opalescent and iridescent effects in col¬ 
ored glass windows by use of opal glass: The latter 
material may be prepared from calcium phosphate or 
bone ash mixed with sand and potash together with 
salt, slaked lime, and broken glass.; one or more of 
these being used. The milky appearance is produced 
by adding one or more of the following arsenic, tin 
peroxide, a ntimonic acid, and silver. The surface of 
the glass may be corrugated or roughened in moulds 
or be hammered, rolled, stamped or otherwise treated. 
In some cases the colored glass may be backed with 
one or more independent layers of opal glass. 


3554 of 1880 to Parry and Colbey. 

Glass, metals for making: A method of making 
various earthy silicates. Native silica, such as sand, 
silicious rock, or slag is fused with salt cake (sulphate 
of soda) and small coal in a furnace or in a glass- 
maker’s pot. The silicate of soda formed is run into 
a receptacle and while hot a jet of steam is thrown on. 
it, which will break it up; or it is allowed to cool and 
is |broken up into pieces which are then steeped in 
water. The silicate is ground and heated with water 
under pressure. The solution obtained is removed and 
treated with caustic lime (milky lime) soluble sulphide 
of calcium, or caustic magnesia, or a mixture of these, 
till precipitation ceases. The liquid is then separated 
from the silicate by means of a filter press. The sili¬ 
cate of lime is used as a substitute for bone ash, ground 
flint, and glass, in the manufacture of porcelain and 
in the manufacture of glass. 





130 


5737 of 1881 to Hewitt. 

Ornamenting glass by applying to' it, while it is in 
a semi-fused state, finely divided metals such as cop¬ 
per, iron, zinc, or antimony, with certain salts or alka¬ 
lies, enamels or caleareous substances, and, in some 
cases, oils or fats. The metals, enamels, etc., may be 
used singly or two or more together, but always with 
a salt, such as sodium chloride, or an alkali. 

The whole is strongly heated and may be covered 
with a thin coat of glass. Or, a mixture of crystals of 
nitrates and chlorides of metal, such as gold and sil¬ 
ver is placed in vessels in which a ball of glass metal 
nTrolled. The mass is subjected to the action of car¬ 
bonic acid, having in some cases, previously been 
“wasted” by immersion in water, and then reheated. 
Glass so ornamental is applicable for making vases, 
drinking glasses, bottles, wall decorations such as 
panels and dados, windows, tiles, plaques and door 
furniture, and for other purposes. 


2278 of 1882 to Lake. 

Materials: Impure sodium sulphate liquors, ob¬ 
tained in a process of making lead oxides and contain¬ 
ing sodium sulphite and other sodium compounds are 
boiled down after removing arsenic and antimony, to 
yield a material for use in glass making. 


3147 of 1882 to Harris, 

Making colored glass for electric or other lamp 
globes, etc.: A ball of flint glass from the pot is mixed 
with a coloring composition and reheated. It is then 
placed in a cup of glass formed with an aperture in the 
bottom and the whole is welded together and blown. 
For transparent coloring, the composition consists of 
pigment mixed with a “fret” of sand, lead oxide, “pot¬ 
ashes,” and antimony. For opaque coloring, the fret 
consists of sand, lead oxide, arsenic and fluorspar. 
For opal effects, calcium phosphate is used instead of 
tin oxide, and red glass is obtained by substituting 
white lead for the lead oxide. 




131 


4131 of 1882 to Claus. 

Materials: Silicates of zinc, lead, baryta, and stron- 
tia made by a special process, are stated to be appli¬ 
cable for use in the manufacture of glass. 

376 of 1883 to Herman. 

Obtaining metal: Relates to methods of utilizing 
the refuse silicious materials from glass works. The 
waste materials are fine sand, after being used for 
grinding, used silica bricks, and flattening stones ; the 
two last require to be crushed before being used. 
Glass of various colors may be prepared by mixing the 
refuse polishing-sand with the ingredients usually used 
in glassmaking. Slag from copper works, refuse from 
the soda ash manufacture (alkali waste), etc., may be 
used in addition to produce certain colors. 

1557 of 1883 to Gatehouse. 

Obtaining metal for glass bottles: Lignite or anal- 
agous substance such as brown or wood coal, is 
treated with a solution of soluble silicate or a mixture 
of silicious earths in powder, or as a slurry with or 
without the addition of soda ash, and when it is found 
to contain from 10 to 30 per cent of silicious matter it 
is distilled in a retort at a dull red heat. The residual 
“carbo-silicum” may be oxidized or calcined, and 
used in the manufacture of glass bottles. 


2252 of 1883 to Colton. 

Obtaining metal: Blast furnace slag, preferably of 
the uni-silicate type, is blown into slagwool by steam 
or air, the fibrous material thus obtained is pressed 
into crucibles, retorts, muffles, or ovens, with or with¬ 
out the addition of such substances as favor reduction, 
and is heated to redness till it is desulphurized, care 
being taken that the temperature is high enough to 
fret but not to fuse the mass. Dark colored particles 
are separated by scraping or washing, and are added 




132 


to the next charge, and the finished mass is pulverized 
for use. If the slag contains sulphate of lime this 
may be first reduced to sulphide. The material may be 
used as a glaze or a body in the manufacture of pot¬ 
tery, in the manufacture of glass, and for making or¬ 
namental plastering stucco, statuary and artificial 
stone in admixture with lime. 


6889 of 1884 to- Johnson. 

Materials for opaque or opalescent glass: Instead 
of cryolite, etc., an alkaline fluoride together with 
kaolin is added to the ordinary materials used in glass 
manufacture. The fluoride may be conveniently 
formed by the addition of hydrofluoric acid to an alka¬ 
line aluminate. The following proportions are suit¬ 
able: 38 parts of alkaline fluoride (containing 90 per 
cent of fluorides), 5 parts of soda, 15 parts of China 
clay, 10 parts of chalk, and 156 parts of sand. 


13433 of 1884 to Stanford. 

Transparent materials: Sodium alginate or alginic 
acid, obtained by special processes, when treated with 
an alkaline silicate forms flexible glass. 


15743 of 1885 to Standen. 

Obtaining metal: A mixture of sand, lime, or simi¬ 
lar substances with metallic oxides and salts is dried, 
pressed and melted, and employed in the manufacture 
of bricks, tiles, etc., for sanitary use, building blocks, 
pipes, slabs and similar articles. Suitable proportions 
for tiles are 100 parts of white sand, 35 of lime, and 
40 parts of sodium carbonate or other salt. 


8023 of 1886 to Shirley. 

Materials for opalescent or stained glass: Variously 
colored and translucent glass is prepared by adding a 
mixture of gold and uraniumjpxides. or gold with 
copper carbonate, or chromium oxides and litharge to 






133 


an aluminous batch. Articles made of this glass may 
be ornamented by removing the outer portion by sand 
blast in the usual manner, or by immersing them in 
a suitable bath, the parts of the surface required to be 
retained being protected by a suitable coating; or by 
applying enamel colors. 


4821 of 1887 to Moore. 

Materials for green opaque glass: To the ordinary 
opaque batch is addedjaxide or a salt of uranium and 
black oxide of copper, or (for a lighter color) per¬ 
oxide of iron and black oxide of copper. Suitable pro¬ 
portions in the latter case are peroxide of iron 30 ozs., 
and black oxide of copper 6 ozs. to each cwt. of batch. 


4822 of 1887 to Moore. 

Materials for opaque glass: To the ordinary opaque 
batch is added flowers of sulphur, calcined oats, or 
other similar substance employed for giving ordinary 
glass a topaz color; a light brown or fawn-colored 
tint is thus obtained. About 8 ozs. of coloring matter 
to each cwt. of batch may be used. 


5270 of 1888 to Chardonnet. 

Transparent and translucent materials: Relates to 
a process for denitrating and dyeing pyroxylin for 
making glass substitutes, etc., which consists in im¬ 
mersing the pyroxylin in nitric acid. The reduction is 
accelerated by increasing the strength of the acid in 
the temperature. For example, the pyroxlin is 
heated to 30° to 40° C. with nitric acid s. g. 1.32 for 
2-24 hours according to the thickness of the threads. 
The material which is thus rendered permeable is 
then washed and passed into a dye vat. When the 
process is also applied to the manufacture of flexible 
glass, or the like, the introduction into the mother 
solution of metallic chlorides for diminishing com¬ 
bustibility is dispensed with. 





134 


8129 of 1888 to Parry and Welsh. 

Obtaining metal: Slate refuse or black-grit is pul¬ 
verized and employed together with cullet and manga¬ 
nese or coloring oxides as material for the manufac¬ 
ture of glass articles. 


11016 of 1888 to Hadden. 

Materials: In forming red glass red oxide of cop¬ 
per and tin dioxide are added to the ordinary batch. 
The following proportions are used; sand 2,000, red 
lead 400, potash 600, lime 100, calcium phosphate 20, 
potassium bitartrate 20, borax 20, red oxide of cop¬ 
per 9, and tin dioxide 13. 


13,211 of 1888 to Rust. 

Materials for glass tiles: A mixture of sand, soda 
ash, native carbonate of baryta, China clay, phosphate 
of lime, nitrate of soda, and arsenic is fused, cooled, 
and powdered, and the powder is mixed with cullet 
and sand and returned to the furnace with the addition 
of metallic oxides for coloring purposes. The vitreous 
molten material is pressed in moulds and annealed in 
an oven. 


2641 of 1889 to Davidson. 

Materials: Articles such as ornamental dishes, 
vases, jugs, tumblers, etc., are made of clear glass at 
the base, the glass gradually becoming more opaque 
towards the top. To a batch of say, 560 lbs, of sand, 
210 lbs. of alkali, and 84 lbs. of sodium nitrate, is 
added 70 lbs. of calcium phosphate, 84 lbs, of calc- 
spar, and 35 lbs, of arsenic. The proportions of these 
three ingredients may be varied. The article is pressed 
and moulded in the ordinary manner, and then allowed 
to cool slightly and reheated. 





135 


2626 of 1890 to Huelser. 

Materials: Opalescent glass is formed by adding 
silicofluorides of alkalies to any glass batch. The fol¬ 
lowing mixture may be employed: cryolite, carbonate 
of soda, chalk, sand, kaolin, and silicofluoride of so¬ 
dium. The cryolite may be replaced by additional 
silicofluoride of sodium. 


16,629 of 1890 to Schulz. 

Materials: Minerals, especially granulite or mel- 
don stone, for use in the manufacture of glass and 
similar goods, are treated with acids, preferably hy¬ 
drochloric, to remove any iron. The minerals are 
afterwards washed, and a little alkali added to neu¬ 
tralize any remaining acid. 


2019 of 1891 to Walker. 

Materials: Silicates for glass-making are obtained 
by steaming and heating a mixture of common sand 
and metallic chlorides, hydrochloric acid being given 
off during the operation. The sand is thoroughly pul¬ 
verized and washed with hydrochloric acid, then mixed 
with chloride of calcium or sodium, or both, and re¬ 
placed in a crucible arranged in a gas-fired regenera¬ 
tive furnace. Steam is introduced through a coil and 
perforated pipes and the hydrochloric acid escapes 
through a pipe. The crucible is mounted on a plate 
so that it may be lowered for emptying. The salt may 
be vaporized and blown into the crucible with the 
steam, or it may be fed from a hopper into the steam 
pipe and there vaporized. Steam may be passed 
through the bottom of the crucible, suitably perfor¬ 
ated for the purpose. Other forms of furnaces may 
be employed. For glass-making, the silicates pro¬ 
duced are mixed with cullet, or with carbonate and 
sulphate of soda, and pulverized coke or charcoal; or 
excess of sand may be used when producing the sili¬ 
cates, so that only the addition of carbonate of soda 
is required. 




136 


5324 of 1891 to Walker. 

Materials: Relates to the process described in Brit¬ 
ish Patent No. 2019 of 1891, and consists in the sub¬ 
stitution of lime for the calcium chloride mentioned 
therein. According to the present process sand, which 
has been washed with hydrochloric acid, common salt, 
and lime are mixed and treated as previously described. 


9,097 of 1891 to William. 

Obtaining metal: The “Blacks” or pieces of glass 
removed from the blowing irons are usually treated 
with hydrochloric or other acid to remove the adherent 
iron scale. The present invention consists in heating 
the acid by means of steam jets forced into it, or by 
a fire placed under the acid bath, so as to increase 
the action of the acid on the scale. 


21,350 or 1891 to Welz. 

Stained glass: Relates to the manufacture of rose 
or orange-red glass. Selenium is added to the vitre¬ 
ous material while in the melting pot to produce rose 
and selenium mixed with cadmium sulphide is used 
for orange-red glass. The tint depends upon the 
amount of selenium or cadmium sulphide employed, 
and the greater the quantity of the latter used, the 
more the color inclines to orange yellow. Colored 
articles can be manufactured directly from the glass. 


3,569 of 1892 to Cay. 

Forming articles with portions of different re- 
frangibility: Relates to the manufacture of globes, 
chimneys, and shades for electric and other lamps, the 
object being to diffuse the light and prevent the flame 
or electric filament from distressing the eye. Grains 
of colorless or colored sand, or other silicious material 
or glass, having a refractive power different from 
that of the material of which the chimneys, etc., are 
made, are introduced or imbedded in the main body 





137 


of the glass. A quantity of the body-glass is worked 
into the desired shape, and marvered on a marver on 
which the silicious particles have been evenly spread. 
The layer thus formed is then covered with an addi¬ 
tional body-glass. 


7,792 of 1892 to Grosse. 

Marbled glass: Glass of any color preferably 
addled or opaque, is worked on the pipe as usual, 
and is then sprinkled over with a finely-pulverized col¬ 
ored glass flux by blowing, sieving, etc. The mass 
is then reheated in the furnace to fuse the flux, and 
is then finished in the usual way to produce sheet 
glass, etc. 


8,865 of 1892 to Lewes. 

Obtaining metal: In order to increase the rapidity 
of the fusion of the grit in the melting-pot, carbonace¬ 
ous material, such as wood, charcoal, is mixed there¬ 
with. The combustion of the charcoal, etc., is effected 
by supplying air or oxygen (preferably heated) to it 
through suitable pipes of refractory material, or by 
using an alkaline nitrate, etc., in the grit in place of 
part of the carbonate usually employed. 

2,033. of 1893 to Welz. 

Materials for stained glass: Glass which appears 
orange yellow by transmitted light, and greenish by 
reflected light, is produced by adding selenium and 
oxide of uranium to the glass metal, while it is still 
in the melting pot. 


4,273 of 1893 to Bohm. 

Strengthening or stiffening thin-walled flexible 
fragile objects formed of glass, etc. The invention 
consists in placing on the inner or reversed side of 
the article a layer of soluble glass, barium sulphate or 
chalk, and sand or powdered glass, stone, or the like. 





138 


A coating of a solution of soluble glass serves to at¬ 
tach the two together. Before the article with its 
backing is perfectly dried, it is dipped into a solu¬ 
tion of calcium chloride. 


10,384 of 1893 to Solms-Baruth. 

Materials; moulding: Relates to the production of 
glass resembling agate. A mixture of basalt, soda, 
borax, carbonate of lime, and sand with a small quan¬ 
tity of silver chloride is finely pulverized and fused 
in melting pots. SmalL pieces of basalt are gradually 
added and finally dichloride of tin is stirred in. After 
purification the glass is ready for working. The glass 
articles should be cooled irregularly, the more quickly 
cooled parts appearing the darkest. In order to ef¬ 
fect the irregular cooling, porous wooden moulds are 
cooled by moistening with water, or metal moulds of 
varying thickness may be used. Or a mould con¬ 
structed with vertical internal grooves and channels 
for the admission of a cooling liquid can be employed. 
By using metallic salts as fluxes, the color may be 
varied, for instance, copper suboxide and tin monoxide 
give a red or black ground color. 


16,018 of 1893 to Kralik and Kralik. 

Materials for stained glass: In place of coloring 
glass by the use of selenium, selenites or selenates 
are employed, these compounds being decomposed by 
the subsequent addition of reducing agents to the mol¬ 
ten metal. Zinc dust is preferably used to reduce 
the selenium compound, arsenious acid, alkaline ar- 
senites, or sulphate of soda, etc., are also applicable. 
}A rose-red tint is obtained. 


22,834 of 1894 to Soc. Anonyme etc. 

Materials: Relates to the production of new opaline 
material by mixing about 54 parts of silica, 39 parts 
of baryta, and 7 parts of soda together. This com¬ 
position is made into plates for covering walls, par- 





139 


titions in bathrooms, etc., or into vessels or other 
articles usually made of earthenware. The material 
may be employed rough or polished and can be orna¬ 
mented or decorated by the ordinary process. 

17,931 of 1895 to Ellis. 

Obtaining metal: Glass is decolorized by the addi¬ 
tion of selenium to it while the glass is in the molten 
state. The selenium may be added either in the me¬ 
tallic form or as a compound, such as selenate or 
selenide, in which case a suitable means of reduction 
for freeing the selenium is employed. Potash glass 
requires a smaller addition of selenium than soda 
glass. The selenium may be added after a preliminary 
decolorizing with nickel, saltpetre, arsenic, etc. 


1,521 of 1896 to Wilsmore. 

Materials: To render glass chimneys capable of 
emitting incandescent light when heated by ordinary 
lamp flames, particles or fibres of any substances 
which become incandescent under the action of heat 
are mixed or incorporated with, or affixed to, the glass 
forming the chimneys. 


5,772 of 1896 to Garchey. 

Moulding: Powdere d gla ss, preferably that charged 
with lime and soda, is mixed with suitable coloring 
materials and placed in an iron mould box having a 
movable bottom capable of sustaining suitable pres¬ 
sure. The mould box is lined with sand, lime, etc. 
The mould is slowly heated till the glass is near its 
fusing point, in which condition it becomes devitrified. 
It is then heated to fusion, and the pasty glass moulded 
under pressure. The article is then removed from 
the mould and annealed. Marble is imitated by scat¬ 
tering over the pastry devitrified glass pieces of col¬ 
ored glass, which, when melted are stirred to and fro 
to form veins, the mass being then moulded under 
pressure. 





140 


22,511 of 1897 to Butterworth. 

Forming articles with layers of diverse composi¬ 
tion: Tubes for water gauges, thermometers, ba¬ 
rometers, and other apparatus subject to high pres¬ 
sures or sudden or extreme variations of temperature 
are made as follows: A quantity of leadcasing glass 
is first gathered on the rod or tube, and over it is 
placed two layers of lime glass of which the inner 
may be intermediate in expansibility between the other 
two. A tube is then formed in the ordinary way from 
this composite metal. 


2,003 of 1898 to Garchey. 

Devitrified glass: Relates to a ceramic stone formed 
of devitrified glass, as described in British Patent No. 
5,772 of 1896. Waste glass together with slag, 
scoriae, porter’s and other clay, or other verifiable 
material is pulverized and sifted. When clay or other 
material not easily fusible is employed, the materials 
are agglutinated with a silicate or gum to form a 
paste that can be roughly moulded to the required 
form, but the powder may be placed in a refractory 
mould without any treatment. Fragments of unpul¬ 
verized glass may be embedded in the pulverized ma¬ 
terial. The devitrification is effected in a furnace at 
a temperature below the fusing point of the materials, 
and the roughly moulded article is finally shaped un¬ 
der pressure between suitable dies. Molten glass may 
be run into moulds, devitrified, and finished in the 
above way. Pieces of colored glass embedded in the 
surface may be employed to give decorative effects. 


1,880 of 1899 to Moser. 

Materials: Relates to the decolorization of glass 
or neutralization of the green tint due to the presence 
of iron. A mixture of manganese peroxide, selenium, 
oxide of bismuth, nickelous hydrate, and arsenious 
acid is added to small quantity of the materials from 




141 


which the glass is made, and the mixture is introduced 
in which the melting pot after melting is proceeded 
to some extent in the furnace. Wet sticks of wood, 
etc., are introduced to produce ebullition and thor¬ 
oughly mix the contents of the melting pot. Vitreous- 
arsenious oxide may be added. 


5,353 of 1899 to Herman. 

Materials: Relates to the utilization of sand which 
has been employed for grinding plate glass, etc., and 
which in consequence contains both glass and iron 
finely diffused through it. The particles of metallic 
iron are removed from the sand either in the wet or 
dry state by the use of magnetic separators. The sand 
is >gUaded, when mixed with water, by passing it 
through settling-pits from which the coarser grains 
may be returned to the grinding benches. The finer 
sand is dried in a hydro-extractor, or in a rotary 
furnace or otherwise, and is then treated with hydro¬ 
chloric acid or other solvent or without the aid of 
heat. The recovery of the acid is effected by com¬ 
pletely wetting the sand with the acid without using 
more than is required for that purpose, allowing water 
to run on the sand and drawing off the acid at the 
bottom of the vessel. 

The water then takes the place of the acid without 
appreciably mixing with it, and as soon as water 
reaches the outlet the stream is diverted. If the sand 
is of the very finest grade, it may be necessary to re¬ 
move the solvent and washing water by subsidence 
and decantation, or by a hydro-extractor, or coarse 
sand may be mixed with the fine sand to render it 
permeable. The product is well adapted for the 
manufacture of glass as it already contains a con¬ 
siderable proportion of the finest glass. 


13,049 of 1899 to Walter and Walsh: 

Materials; moulding: Copper or brass filings are 
melted with sand and soda to produce an opaque 




142 


golden-yellow glass called “aventurine” which is filled 
with specks or spangles of a bright gold color. In 
cooling, the mass breaks into a number of small pieces. 
Large aventurine articles are produced by welding, 
melting the fragments together in a mould, with or 
without the addition of other kind of colored glass. 
In order to prevent oxidation of the metal particles, 
the mould, mulfflies, kiln or oven is entered or closed 
to prevent access of air to the melted mass. 


16,780 of 1899 to Rhoden. 

Materials: Orthoclase felspar is mixed and heated 
to a bright yellow heat with lime and common salt 
and the soluble potassium salts obtained extracted. 
The residue, consisting approximately of 60 per cent 
of silica, 30 per cent of lime and 10 per cent of 
aluminum may be used for making glass. 


16,781 of 1899 to Zsigmondy. 

Ornamenting: Solutions for producing purple, Ver¬ 
million, and rose lustre-colors on glass, etc., are pre¬ 
pared by mixing one part by weight of gold with from 
0.2 parts by weight of silicic acid in the form of an 
organic silicide. The silicide solution is obtained by 
mixing an alcohol, essential oil, or solution of resin, 
or a mixture of liquids, with chloride of silicon, and 
evaporating the chlorine. Instead of the chloride of 
silicon, bromide, iodide, fluoride, oxychloride, or 
chloroform of silicon may be used, and a ketone, mer¬ 
captan, aldehyde, or non-saturated hydrocarbon may 
be substituted for the alcohol. The colors or tints 
may be varied by the addition of resinates or organic 
compounds of silver, lead, zinc, barium, strontium, 
calcium, bismuth, cerium or zirconium. The silvery 
lustre-colors are fixed by heating the article in closed 
muffle at a comparatively low temperature. 


8,309 of 1900 to Knospel. 

Materials: Barium, or barium compounds, such as 
carbonate, chlorate, hydrate, nitrate, oxide, or sul- 





143 


phate, are employed as fluxes, instead of potassium 
carbonate in making glass containing calcium phos¬ 
phate, to be partially or wholly opaque and colored 
and easily moulded. 


9,353 of 1900 to Ziegenbruck. 

Ornamenting: Boracic solutions are added to pig¬ 
ments or glazes used in producing “lustre ware” and 
form borates when the articles are baked or fired. 
Cobalt lustre combined with the boracic solution will 
give a beautiful blue color enamel, while solutions 
containing gold will impart purple, red and pink col¬ 
ors to glass, etc. The boracic solution may be ob¬ 
tained from boron chloride and alcohol, or borax and 
ether sulphate, or by heating isobutylic alcohol with 
fused boracic acid, or otherwise. 


18,152 of 1900 to Leuchs and Leuchs. 

Coating: Relates to the manufacture of opaquel 
or clouded glass or enamels by the employment of 
titanic acid. Burnt titanic acid, particularly that ob¬ 
tained by chemical means, is mixed or ground with 
finished glass or enamels, to form a compound which 
is applied as a coating to glassware, the coating be¬ 
ing burnt on. 


1,491 of 1901 to Sudre and Thierry. 

Transparent materials: Pure, vitreous, amorphous, 
and homogeneous products for various purposes are 
obtained from natural or artificial oxides or mixtures 
or compounds of oxides with fusing points not less 
than that of pure alumina, by fusion in a vacuum or 
inert atmosphere under radiant heat of an electric 
furnace with one or more arcs, and out of contact with 
the electrodes. The materials treated include siLica, 
alumina, lime, magnesia, glucina, rare earths, ferric 
oxide, zinc oxide and etc. chromite, aluminum, cal¬ 
cium, magnesium, etc., aluminates, calcined dolo¬ 
mite, bauxite, etc. After fusion, solidification is 





144 


effected by sudden cooling, as with cast iron or 
steel, and the cooled mass may be reheated, as 
with glass or malleable cast iron. The fused 
matters may be cast, rolled, stamped, forged, 
welded, blown, or drawn. Articles produced from 
these are almost insensible to temperature below the 
fusing point of iron and some of them acquire trans¬ 
parent and reflecting properties. The products may 
replace glass, crystal, porcelain, faience, earthenware, 
stoneware, and all the products of the glass making 
and ceramic arts. Metal also may be replaced when 
high temperatures, chemical action, or mechanical ef¬ 
fects are to be resisted. Metallic skeleton or frame 
works may be embedded in the fused products for 
strength. Applications include fused silica for chem¬ 
ical vessels, carboys, retorts, crucibles, flasks, mortars, 
etc. 


4,495 of 1901 to Geille. 

Obtaining metal; moulding; ornamenting: Relates 
to the manufacture of decorative objects, such as 
plaques or facing blocks, from glass waste, etc. The 
waste glass is mixed with a compound composed of 
fluor spar, lunestone, soda, and felspar, and the mix¬ 
ture is then heated until it is partly melted. It is 
then compressed in moulds of the required form. 
Broken glass is sometimes pressed into one of the 
faces of the article, to facilitate attachment to walls, 
etc. The right side of the article is heated, to render 
it more or less brilliant. Oxides may be added to 
the mixture to color it. In some cases, the face of 
the block is formed with a raised design, which is 
filled in with powdered colored glass, which is more 
fusible than the body and is applied by a sifter. The 
article is then heated to fuse the colored glass. 


12,589 of 1901, to Garchey. 

Devitrified glass; obtaining metal; moulding; orna¬ 
menting.—Relates to improvements in the manufac- 




145 


ture of the “glass stone” described in British Pat¬ 
ents No. 5,772 of 1896, No. 2,003 of 1898, and 
No. 5,885 of 1900. Instead of preparing the glass 
stone from old glass, crushed or pulverized new glass 
is employed, which is poured into suitable moulds of 
thick metal, such as cast iron, and is transferred 
as soon as it becomes tacky or pasty, to moulds of 
sand, lime, plaster, talc, etc., placed in the rotary 
hearth of a devitrifying kiln or surface. Agrillace- 
ous or calcareous sands may be added to the glass. 
When the sand mould containing the devitrified glass 
returns to its starting point in the kiln, the slab, etc., 
is removed and transferred to a hydraulic press, which 
gives it the exact form required. To ornament the 
surface of slabs, flags, or tiles, the bottom of the 
mould may be sprinkled with enamel powder or with 
glass fragments. The glass stone is well adapted to 
receive an electrolytic deposit of copper or other metal, 
which can be worked, polished, engraved, etc. The 
electrolytic process is applicable in the manufacture 
of electric insulators, condensers, electrodes, etc., 
from the glass stone. 


5,242 of 1902, to Zsigmondy. 

Stained glass; materials:—Relates to the manufac¬ 
ture of rich glass, in which the coloration is effected 
by gold; and consists in employing a glass composi¬ 
tion containing a barium compound, and in using a 
quantity of gold not exceeding from .25 to 1.7 parts 
of gold for every ten thousand parts of silica present 
in the composition. 


9,405 of 1902, to Becker. 

Materials:—Relates to the utilization of'glass-gall 
to obtain glass therefrom. A small quantity of graph¬ 
ite is added to the sulphate mixture, sufficient to re¬ 
duce the sulphates in the glass-gall, but not in suf¬ 
ficient quantity to color the glass. 




146 


' i \ 


28,955 of 1902, to Becker. 

Obtaining metal:—In order to prevent the crum¬ 
bling, etc., of the mixture of raw materials when 
smelting by means of the electric arc, etc., they are 
first mixed into a paste with water, and then placed 
in a suitable vessel and dried at from 40° to 50° C. 


10,040 of 1904, to Devillers. 

Ornamenting:—Relates to the formation of imi¬ 
tating marble slabs, etc. Scafes from small burst 
bubbles of colored glass, which has been refined in 
a liquid condition in an earthenware vessel, are ap¬ 
plied to the surface of panes or sheets of window or 
other glass, being fixed on by cement. Liquid or 
powdered enamel with or without sand, is then 
sprinkled in, and the whole fixed at about 800° C., 
and cooled gradually. The imitation marble slabs 
formed are used for walls, chimneys, washstands, 
bricks, etc. 


20,880 of 1904, to Bredel. 

Obtaining metal; moulding:—In the manufacture 
of quartz glass, rock crystal, etc., is broken into small 
pieces, heated to about 1,000° C., and thrown into 
water. This is repeated in order to diminish the co¬ 
efficient of expansion of the resulting glass. If quartz 
sand is employed, it is first melted and cooled, then 
treated as above. The material thus obtained is melted 
and transformed into a fibrous or woolly form by a 
jet of steam or hot air. The woolly mass is pressed 
or moulded into the required form, and remelted, 
preferably from the bottom in order to avoid the 
formation of air bubbles. 

3,906 of 1905, to Johnson. 

Obtaining metal; materials:—Relates to a process 
for obtaining quartz glass free from air bubbles from 
rock crystal. The crystal is broken into pieces about 




147 


the size of a hazel nut, and heated to a temperature 
somewhat above 600° C. The pieces are then re¬ 
moved singly, by heated tongs, etc., so as to avoid 
cooling, to an electric or oxyhydrogen furnace, where 
they are fused. In the case of an electric furnace, 
each piece is added only when the previous piece is 
fused, and in that of an oxyhydrogen furnace, the 
pieces are fused separately and brought together in 
the fused state. 


15,375 of 1905, to Timm. 

Obtaining metals. Relates to the preparation of 
blast furnace slag, for the manufacture of glass and 
the like, and consists in allowing the molten slag 
to flow downwards through a heated mass of the flux 
or other material with which it is to be admixed, 
so that a homogeneous solution of the latter takes 
place. A mixture of flux and coke is periodically in¬ 
troduced into a blast furnace through hoppers, while 
molten slag is continually admitted through a funnel, 
the contents of the furnace being maintained in an 
incandescent state. The material flows out through 
a passage. The most commonly used flux is lime, 
but ferric oxide, pyrolusite, alkali, and other sub¬ 
stances may also be employed according to the nature 
of the material required. Gaseous or other fuel may 
be used instead of coke. 


15,630 of 1905, to Bredel. 

Obtaining metal:—Consists in a method of pro¬ 
ducing clear molten quartz at a) low temperature. 
Quartz or other forms of silica that have been sub¬ 
jected to the preliminary treatment described in Brit¬ 
ish Patent No. 20,880 of 1904, to prevent splitting 
when heat is applied is broken into small pieces and 
heated in a suitable vessel, such as a muffle or tube, 
to 1,200° C. by external heat. The object is to re¬ 
move the air bubbles, which are present and which 




148 


retard the production of a clear liquid. For this 
purpose, a stream of hydrogen, or an oxyhydrogen 
flame containing an excess of hydrogen is introduced 
into the melting mass, which at 1,200° C. is permeable 
to hydrogen. The oxygen of the air bubbles combines 
with the hydrogen to form water, the vapor of which, 
together with the residual nitrogen, is expelled from 
the mass. At this stage an oxyhydrogen flame con¬ 
taining an excess of hydrogen is introduced into the 
mass, instead of the hydrogen'or flame with excess 
of hydrogen the effect being to remove the hydrogen 
which was retained in this quartz. The temperature 
of the clear quartz is then about 1,950 to 2,000° 
G, or 300° lower than it can be obtained by the older 
process. 

16,165 of 1906, to Jonkergouw and Destrez. 
Moulding; obtaining metal; stained glass:—A mix¬ 
ture of sand, chalk, borax, minium and carbonate of 
soda, with or without the addition of metallic oxides 
for coloring is melted. The resulting mass is thrown 
into water, finely ground to a paste, and packed into 
moulds, which are then placed in a furnace till the 
materials are fused. Articles composed of several 
differently colored glasses may be made by packing 
each mould with several different pastes prepared as 
above described. The moulds are made of a mix¬ 
ture of clay, kaolin, quartz and burnt plaster in order 
to prevent the finished article from adhering. 

5,123 of 1907, to Bloxam. 

Obtaining metal:—In the manufacture of a cera¬ 
mic material, a highly siliceous glass is first prepared 
by fusing together quartz, alkaline earths, lime, and 
products containing alumina, preferably in such pro¬ 
portions that the mass may contain not less than 75 
per cent of silica, and not more than 10 per cent of 
alkali, 10 per cent of alumina, and 8 per cent of lime. 



149 


The glass is subsequently granulated and incorporated 
with other ingredients. 

8,704 of 1907, to Lindemann. 

Obtaining metal.—Glass which is transparent to 
X-rays and to light of very short wave-length, and 
hence specially adapted for the manufacture of Ront- 
gen-ray and like optical apparatus is made by fusing 
a mixture of the oxides of elements having low atomic 
weights, preferably below twelve. For example, a 
mixture of the oxides of lithium, boron, and beryl¬ 
lium may be used. Borates, fluorides, or carbonates 
of such elements may also be employed. 

25,655 of 1907, to Seemen. 

Obtaining metal:—Refractory oxides such as sil¬ 
ica, alumina, magnesia, or lime or compounds of these 
are fixed with oxides of metals of the iron group or 
with titanium oxide in the presence of oxygen, to 
avoid contamination by reduction. The products, 
which are electrically conductive at ordinary tempera¬ 
tures, may be used for heating by electricity. The 
oxygen may be supplied by an oxidizing agent such 
as saltpetre, or in gaseous form. The mixtures may 
be natural or artificial, and may contain 15 per cent 
of iron oxide, 10 per cent of alumina, or 5 per cent 
of titanium oxide. An electric furnace is preferably 
used for the fusion. The specification in the orig¬ 
inal form as published under the act of 1901 states 
that manganese dioxide and zinc sulphate may be used 
as oxidizing agents; the oxides or metals of the iron 
group or of titanium may be used alone, metals may 
be used and oxidized in the fusion; and bodies of 
uniform chemical composition but of varying con¬ 
ductivity in different parts may be produced. This 
subject-matter does not appear in the complete speci¬ 
fication. 




150 


15,963 of 1908, to Schanz. 

Materials:—Glass to be used as a light filter to 
absorb ultra-violet rays contains chromium in small 
quantities, or lead in small quantities, and in addition 
uranium, copper, cadmium, iron, silver, gold, selen¬ 
ium, carbon or phosphorous. The whole of the in¬ 
gredients may be added to a neutral glass, or two lay¬ 
ers, one containing chromium, and the other the ad¬ 
ditional substances may be used, or neutral glass may 
be coated by “flashing.” ' 

14,761 of 1909, to Farjas. 

Production of metal.—Radi o-active glass is ob¬ 
tained by adding pure radiumsulphate" oFsufphates or 
carbonates treated with radium to the materials used 
for glass-making. According to an example a trans¬ 
parent glass is obtained by melting together, barium 
sulphate treated with radium, silica, sulphur and fus¬ 
ible white glass; the sulphur may be replaced by char¬ 
coal; an opaque glass is obtained when a smaller pro¬ 
portion of silica is used. According to another ex¬ 
ample, barium carbonate treated with radium, sil¬ 
ica, and fusible white glass are employed. The glass 
may be made into plates, tubes, filaments, etc., for 
medical and other purposes. 

19,385 of 1909, to Rudolf. 

Production of metal.—Opaque glass for making 
stoppers is produced by adding bone ash, Greenland 
cryolite, etc., to ordinary white or half-white glass 
while in a fused state. 


19,908 of 1910, to Rible. 

Production of metal; annealing.—Volcanic or other 
fusible rock is insufflated with air or gas when in a 
melted condition, so as to form pores in the ma¬ 
terial. Before the temperature has fallen to 500° 
C., the material is reheated and annealed at 800° 






151 


G.; it is then slowly cooled. Air may be introduced 
through tuyeres in the melting pot, or through quartz 
or other non-fusible pipes; or substances that produce 
gas at the temperature employed may be introduced 
into the molten mass suitable materials being car¬ 
bonate of lime, bicarbonate of soda, gypsum, sawdust, 
carbon, graphite and some kinds of basalt. Crucibles 
made of or lined with plumbago, coke or carbon may 
be used to give the gas. 

1,859 of 1911, to Kersten. 

Production of metal.—Artificially manufactured 
alkali meta-silicates are added as fluxes to the con¬ 
stituent glass mixture in place of % the usual alkali 
carbonates or sulphates. The alkali meta-silicates are 
obtained by dissolving crystalline silicic anhydride in 
alkali lyes under a pressure of about 25-30 atmos¬ 
pheres at a temperature of about 100-300° C. 


16,603 of 1911, to Eddy. 

Production of metal.—A small amount of a color¬ 
ing material is incorporated in the glass of a backed 
mirror, to balance the other color components in the 
glass, whereby the selective absorption of this color¬ 
ing material compensates for the selective reflection 
of the mirror, and tends to produce the image in which 
flesh color tints are sustained. A suitable glass may 
be made from 100 parts of white quartzose sand, free 
from iron, 33 parts of refined potash, 14.5 parts of 
slaked lime, 0.16 parts of manganese peroxide, 5 parts 
of litharge and 0.00002 part of purified gold chloride. 
The ingredients are fused, cast into a plate, annealed, 
ground, polished and silvered. 

18,053 of 1911, to Burckhardt. 

Production of metal.—Glass, similar in properties 
to silica glass, but more easily workable is produced 
by melting silica or pure natural quartz free from 
water, to which one or more acidic oxides of the 





152 


fourth group of the periodic system, for example, ti¬ 
tanic acid or zirconium oxides, have been added. 


26,091 of 1911, to Hailwood; 

Forming articles with metal skeletons and the like.— 
A lamp glass for miners’ safety lamps is strengthened 
by asbestos fibre, thread, etc., which is mingled with 
the glass while molten or semi-molten. 

1,136 of 1912, to Vereinigte 'Chemische Fabriken 
Landau, Kreidl, Heller & Co. 

Opaquing agents for white enamels, etc. consist 
of a hydrated compound of a suitable metal as tin, 
titanium, zirconium, aluminum, etc., containing a 
small amount of alkali or having part of the water 
of hydration removed. 

16,787 of 1912, to Vereinigte Chemische Fabriken 
Landau, Kreidl, Heller & Co. 

Production of metal.—Anhydrous zirconium com¬ 
pounds poor in alkali are prepared for use as cloud- 
eniug-agents for white enamels, etc., by partially re¬ 
moving the combined alkali from alkaline zirconium 
compounds by means of a solution of a salt capable 
of reacting with the alkali and forming a soluble 
alkali salt; preferably the salt of a metal such as tin 
or aluminum, the oxide or hydroxide of which has a 
cloudening effect, is used. For example, zircon is 
partially or completely opened up by heating with 
sodium hydroxide or carbonate, and the soluble sili¬ 
cates and surplus alkali are then removed by means 
of water. The combined alkali is partially removed 
by treating the mass with ammonium, or metal salts, 
and the product is then heated until the water of 
hydration is removed. 

18,300 of 1912, to British Thomson-Houston Co. 

Production of metal; forming silica-glass ar¬ 
ticles:—Silica is added to sodium or potassium mag- 






153 


nesium-boro-silicate, known as “low-expansion glass,” 
to form tough glasses containing over 73 per cent of 
silica having high melting points and low expansion 
and coefficients, for use particularly in making those 
parts of containers into which metallic conductors are 
to be sealed. Containers made of silica glass can 
be connected by intermediate layers of these glasses 
of graded composition and expansibility, to a pure- 
boro-silicate glass in which electric leading-in wires 
of tungsten or molybdenum make vacuum-tight seals; 
or the boro-silicate glass can be connected in turn by 
other known glasses to lead glass into which platinum 
wires may be sealed. A boro-silicate glass contain¬ 
ing 71-72 parts of silica, 3-4 parts of magnesia, 11- 
12 parts of boric oxide, and 12-13 parts of sodium 
oxide, has a coefficient of expansion of 3.5xl0 6 . Sil¬ 
ica in percentages of 15, 30, 50, 70 and 85 may be 
added to form glass for use as intermediate layers 
between this glass and pure silica glass, and at least 
three further layers of greater expansibility should 
be used between this glass and lead glass having co¬ 
efficient of expansion of 9xl0 6 . Such layers may suc¬ 
cessively be fused on to a silica article by an oxygen 
blowpipe, or an electric arc. 

19,849 of 1912, to Vereinigte Chemische Fabriken 
Landau, Kreidl, Heller & Co. 

Production of metal.—Relates to hydrated or anhy¬ 
drous metal compounds containing alkali for cloud¬ 
ing white enamels, glass, etc., as described in British 
Patent No. 1,136 of 1912, and 16,787 of 1912, and 
consists in using from 2 to 7 per cent of alkali, the 
amount being preferably between 3 and 4 per cent. 

25,238 of 1912, to Siemens-Schuckertwerke Ges. 

Production of metal.—The reflector used with a 
projector such as an arc lamp is made of transparent 
glass having a coefficient of cubical expansion of less 




154 


than 2.5x10.5. A suitable glass is boro-silicate glass 
in which chalk and carbonate of soda are more or 
less replaced by boracic acid. 

27,954 of 1912, to Rickmann. 

Production of metal.—A mixture of an antimonate 
and antimony tetroxide is used as coloring agent for 
white glazes, glass and enamel. The mixture is 
formed by heating the metal antimony, antimony ox¬ 
ide, or antimony sulphide to incandescence with a 
saltpetre and alkaline hydrate so that part of the an¬ 
timony is converted into antimonate, while the re¬ 
mainder is converted into tetroxide of antimony. For 
example, the antimony or antimony compound is 
heated in an open furnace with caustic soda and so¬ 
dium nitrate or with caustic potash and potassium 
nitrate. The reaction product, after being washed 
and ground, is either added to the raw material form¬ 
ing the enamel and melted therewith or is ground 
with already melted enamel and the mixture again 
melted. Other white coloring agents may be used in 
addition to the above-mentioned substances. 


29,382 of 1912, to Vereinigte Chemische Fabriken 
Landau, Kreidl, Heller & Co. 

Production of metal.—In the manufacture of white 
enamel, glass, etc., wherein metal compounds poor in 
alkali, and in hydrated form are employed as'cloud- 
ening agents as described in the parent specifications 
and in British Patent No. 19,849 of 1912, the amount 
of water and hydration contained in the hydrated 
oxide used as the opaquing agent is varied in inverse 
proportion to the percentage of alkali used. From 
2 to 7 per cent of alkali may be used with hydrate 
water varying from 15 to 2 per cent. The invention 
is not applicable to tin compounds. 




29,577 of 1912 to Siemens-Schuckertwerke. Ges. 

Production of metal: The reflectors of projection 
apparatus are made from glass in which the capacity 
for resisting thermal effects is increased by the addi¬ 
tion of boron or zinc, or both these substances. 


7,864 of 1913, to Sanoscop. Glas Ges. 

Production of metal: Glass having the property of 
absorbing the ultra-violet rays is produced by adding 
to the ordinary constituents of glass, rare earths of 
the series thorium, lanthanum, cerium, samarium, 
erbium, praseodymium and neodymium. Salts of 
heavy metals may be added in very small quantities to 
act as decolorizing agents. The glass may be used for 
spectacle and other lenses, lamp shades, mercury- 
vapour lamp bulbs. 


12,626 of 1913 to Humann. 

Production of metal: Sodium aluminium-fluoride 
2A1 2 F 6 6Na F, obtained by reacting on sodium fluo- 
silicate with aluminium oxide or hydrate in the pres¬ 
ence of an excess of hot water sufficient to dissolve 
the silica as a colloidal solution may be used as an in¬ 
gredient of bone glass. 


14,760 of 1914 to Boardman. 

Production of metal: Screens or bulbs for electric 
incandescent lamps are made of glass which is tinted 
by adding to the glass batch or mixture black oxide of 
cobalt with about one-fourth its weight of calcined or 
oxidized iron, in order that the transmitted light may 
resemble daylight in tint. 


10,161 of 1914 to Becker. 

Production of metal. Crystalline glass products re¬ 
sembling stone, granite, etc., are manufactured by 
heating the raw materials for glass making (for in¬ 
stance sand, soda, lime, clay, etc.), until incipient fu¬ 
sion takes place, and then removing the mass from the 







156 


furnace or beyond the range of smelting temperature 
and coating or annealing as usual. 

10,488 of 1914 to Davis, 

Forming lenses: In the manufacture of colored 
lenses, plates, prisms, etc., more especially for railway, 
shipping, lighthouse and other like purposes, ordinary 
commercial colored sheet glass is coated with a thin 
layer of fusible siliceous compound consisting of 
silica, red lead, borax, pearlasb, saltpetre or other 
like ingredients. The sheet is bent under heat to the 
required shape in a mould, during which process the 
cement is fused and forms a transparent coating on the 
glass. Molten clear white glass is then applied to the 
sheet and moulded to the required form. 


20,827 of 1914 to Glasgow. 

Production of metal. A glass for use as in color 
screens, electric lamps, shades, etc., comprises a single 
homegeneous glass containing nickel and copper, or 
cobalt or both. Potash lime glass is preferably used. 


21,231 of 1914 to Craig. 

Production of metal: The siliceous residues result¬ 
ing from the treatment of bauxite or other aluminous 
ores, China clay, or calcined coal measure shales with 
sulphuric acid for obtaining aluminous compounds are 
utilized for the manufacture of glass. The residues 
are mixed with suitable material such as lime, calcium, 
etc. Sodium carbonate to neutralize the acid and other 
materials may be added. 


11,083 of 1915 to Eyer. 

Antimonates of alkaline earths, aluminum, mag¬ 
nesium, zinc, tin, zirconium, beryllium, etc., for 
use as clouding agents for enamels and glass, are pro¬ 
duced by heating a mixture of antimony oxide and a 
metal oxide with ammonium nitrate until the ammo¬ 
nium nitrate is driven off. 






157 


100,738 of Aug. 16, 1916, to Corning Glass Works 
(assignees of Sullivan and Taylor). 

Baking dishes, etc. are made of transparent glass 
with the under surface of the bottom slightly con¬ 
cave, and the upper surface quite flat. A number of 
components for sodium borosilicate glass suitable for 
the ware, and in which the percentage of silica is not 
less than 70 per cent of the total and the percentage 
of boric oxide to sodium oxide is not less than two to 
one, are described. Alumina may be present in an 
amount not exceeding 3 per cent of the total. Com¬ 
positions are given in which the sodium oxide is re¬ 
placed by potassium oxide or lithia. 


101,685 of Nov. 29, 1916, to Strandh. 

In manufacturing glass, particularly when the al¬ 
kalis are added as sulphates, the batch mixture is di¬ 
vided into two portions, which are placed in the fur¬ 
nace separately, so that the first portion, which con¬ 
tains alkaline sulphates, silica, and carbonaceous mat¬ 
ter, is melted before the second portion, containing, 
say, compounds of calcium and silica, is added. The 
alkaline sulphate is converted into silicate during the 
melting of the first portion, and the remaining portion 
is then added. A modified method is also described. 
Calcium carbonate, arsenious acid, or other gas pro¬ 
ducing substance may be added during the later stages 
of the melting to cause the mass to be stirred by the 
escaping gases. 



158 


German Patents. 

No. 31,112. Process for producing milk glass or 
enamel by the addition of alkali fluorides. Te- 
desco. April 29, 1885. 

Alkali fluorides are added to the glass mixture. The 
alkali fluoride is produced by treating alkalis such as 
alkaline carbonates with fluoric acid, or by the action 
of fluoric acid on an alkali aluminate. 

In the first case it is preferable that the alkali should 
be in excess. When using this preparation, clay is 
also added to the glass. 

In the second case, a mixture of alkali fluoride and 
clay is produced, which can be employed as such. 


No. 33,425. Improvements in the process of produc¬ 
ing milk glass or enamel by the addition of al¬ 
kali fluoride. Tedesco. May 7, 1885. 

This is an addition to German Patent No. 33,112. 
Instead of the alkali fluorides mentioned in No. 
33,112, the acid alkali fluorides are used. 


No. 61,777. Process for producing milk glass. Kemp- 
ner. May 18, 1892. 

The sodium in the batch of glass is partially or en¬ 
tirely replaced by equivalent quantities of sodium or 
lead oxide, or about five per cent of clay or a-clay com¬ 
pound, or boric acid are added. 


No. 63,558. Process for producing rose-red and or¬ 
ange red glass. Welz. Aug. 24, 1892. 

Selenium alone, or mixed with cadmium sulphide is 
added. In the first case a rose red color, in the second 
case an orange red color is produced. 





159 


No. 69,979. Process for the Manufacture of Milk 
Glass. Hirsch and Yedesco. Aug. 30, 1893. 

Milk glasses to which cryolite or other fluorides 
have been added, together with clay, to make them 
translucent, become opaque after a short time, espe¬ 
cially after heating. To prevent this aluminum, and 
carbon or substances that will produce carbon in the 
glass mixture, are added. This also conserves the 
pots. 


No. 73,348. A process for making a glass, that has 
an orange-yellow color in transmitted light, and 
a greenish color in reflected light. Welz. March 
21, 1894. 

This is an addition to German Patent No. 63,558. 

According to the main patent, selenium and cad¬ 
mium sulphide are added to the glass in the pot to pro¬ 
duce an orange red glass. 

The cadmium sulphide is now replaced by uranium 
oxide. 


No. 74,565. Process for Imparting a Red Color to 
Glass by Means of Selenites and Selenates, 
Spitzer. June 6, 1894. 

This refers to the process of German Patent No. 
63,558. A selenite or selenate (of potassium, sodium, 
or calcium) is added to the molten glass and the color¬ 
ing selenium separated out by a known reducing agent 
as arsenious acid, etc. 


No. 77,737. Process for imparting a red color to 
glass by means of selenium compounds. Spitzer. 
Dec. 12, 1894. 

This is an addition to German Patent No. 74,565. 

Selenium is now added to the glass instead of sele¬ 
nites and selenates. To secure new shades, gold, sil¬ 
ver, coloring metallic oxides, bone, cryolite, etc., can 
be added. 





160 


No. 88.441. Process for producing a copper-ruby 
glass of any desired gradation of color. Goerisch 
& Co. Oct. 14, 1896. 

Antimony is added to copper-ruby glass of any de¬ 
sired composition, to reduce the copper oxide found 
in the glass to the metallic state. 


No. 88,615. Process for decolorizing glass by means 
of selenium and selenium compounds. Richter. 
Nov. 4, 1896. 

Selenium or its compounds impart a rose red color 
to glass according to German Patents No. 63,558 and 
No. 74,565, when added to large quantities, but very 
small quantities thereof serve to decolorize glass. 
From 1-5 gms. of selenium are sufficient to-decolorize 
a mass of glass, to which 100 kgs. of sand have been 
added. 

The preliminary decolorizing of the glass can also 
be accomplished by the usual substances as manganese 
and saltpeter, and then the highest grade of white pro¬ 
duced by selenium or its compounds, 

99,165. Process for producing an opaque glassy flux. 
Dickmann and Rappo. Nov. 2, 1898. 

For 5-25 per cent of the fluorides or silicio-fluorides 
of tin or cerium are added Rrthe glass, according to 
the degree of opacity desired. 


No. 103,441. Process for decolorizing glass. Dross- 
bach. July 19, 1900. 

Compounds of neodymium or erbium containing 
small quantities of cerium and praseodymium are add¬ 
ed to the glass. The blue-green color of ordinary glass 
is removed by the rose red color of the erbium or neo¬ 
dymium. 





161 


No.t06,078. Asbestos glass and process of manufac¬ 
ture thereof. Sachsiche Glasswerke, etc., Jan. 
17, 1900. 

This consists of glass and an enclosed body or cover¬ 
ing of woven textile fabric. The production is essen¬ 
tially the same as that of wire-glass. However it is 
necessary to fasten the asbestos fabric on stiff bodies 
made of paper or other burnable material, to give it 
the necessary hold. 


108,595. Process for decoloring glass according to 
German Patent No. 88,615. Moser. April 19, 
1900. 

This enables the glass to be decolorized with cer¬ 
tainty, and to then have a superior polish. 

A mixture of 30 parts (by weight) of manganese 
dioxide, 25 part of selenium, 20 parts of bismuth 
oxide, 15 parts of nickel hydroxide and 10 parts of 
arsenious acid as used. This may be mixed with a 
batch of glass and added to the molten j^lass. 


No. 126,728 Frit for the ordinary kinds of glass, es¬ 
pecially for colored glass for bottles, Becker, Feb. 
12, 1901. 

In order to utilize the ashes of lignite or peat, these 
are added to the frit for ordinary kinds of glass in pro¬ 
portions which are regulated by the content of the 
ashes in compounds of calcium, iron, manganese, and 
clay. 

133,502. Process for imparting a red color to glass 
by means of carbon. Meurer, Sept. 10, 1902. 
Carbon in the form of. carbon black is added to the 
glass. To prevent the creation of dust, the carbon 
black is pressed together, preferably with the addition 
of a binder, as sugar solution, etc. The pressed mass 
is ground to a powder which does not form dust, and 
is thus added to the glass. The carbon black can also 





162 


be saturated with melted alkaline salts or aqueous 
solutions thereof, and added to the glass after drying. 

133,943. Process for producing glass made partially 
or completely opaque by means of calcium phos¬ 
phate. Knospel. Oct. 1, 1902. 

In making such a glass the potassium carbonate of 
the batch of glass is replaced by barytes or its chemical 
compounds. 


No. 138,281. Process for making heavy gold-ruby 
glass from batches of glass containing barytes. 
Zsigmondy, Feb. 11, 1903. 

Enough dissolved or finely divided gold is added un¬ 
til 10,000 parts of sand have from 0.25 to 1.7 parts of 
gold by weight. Then the materials are melted in the 
glass oven. Sodium is suitable as the chief alkali, and 
barytes may be employed. A reducing means may be 
employed during the melting. 


No. 162,607. Process for decolorizing masses of 
glass, Kersten, Oct. 11, 1905. 

The decolorizing is accomplished by titanium com¬ 
pounds and a reducing agent. 


No, 165,986. Process for Manufacturing Milk Glass, 
Kempner, Jan. 31, 1906. 

The glass is made of sand, soda and feldspar poor 
in lime and sodium fluo-silicate in the proportion of 
two to one. 


No. 182,266. Process for Manufacturing Dark Glass 
from Brown Coal Ashes. Allendorff, May 8, 
1907. 

The ashes are mixed with water in tall vessels so 
that their constituents separate in layers, according to 
their specific gravity. The magnesium compounds and 
clay are removed and the remaining mixture of iron 
oxide and lime as well as the necessary sand and other 
ingredients are made into glass. 






163 


No. 189,634. Process for Producing Translucent 
Glasses and enamels. Chemische Fabrik Gus- 
trow, etc., Nov. 13, 1907. 

This is done by the use of zirconium oxide or sub¬ 
stances containing it. 


No. 193,420. Process for Producing Dark Glass. 
Allendorff, Feb, 19, 1908. 

This is an addition to German Patent No. 182,266. 
Peat ashes are subjected to the separation by the 
water instead of the brown coal ashes. 


No. 193,421. Process for Producing Dark Glass 
from Brown Coal Ashes and Peat Ashes. Al¬ 
len dorff, Feb. 19, 1908. 

This is an addition to No. 182,266. 

The clay and the magnesium compounds are sepa¬ 
rated by a flushing process before the dark glass is 
made. 


No. 197,663. Process for Making a Dark Colored 
Glass Impervious to Actinic Rays. Sackur, June 
24, 1908. 

The glass is painted with a mixture of silver sul¬ 
phide or silver sulphate or a mixture of both, and 
heated to 400-450° C. 


No. 218,316. Process for Darkening Glass and 
Enamel. Lesmuller, March 2, 1910. 

This is done by the oxides of quadrivalent elements 
as silicon, tin, lead, titanium, zirconium or thorium. 
These oxides are employed either singly or as mix¬ 
tures, and are melted together with substances con¬ 
taining boric acid in such proportion that the melted 
boric acid is saturated with the said oxides. The 
melted substances are subjected to the action of steam, 
or acid vapors while they cool, either when mixed with 
the glass or enamel, or else a dark borate glass can 
be first made and then added to the glass or enamel to 
be darkened. 






No. 240,085. Glass. Stock, Nov. 29, 1911. 
Rubidium is added to the glass. 


No. 249,647. Process for Producing Melted Glass 
with the Use of Artificial Alkali Silicates as a 
Flux. Kersten, Aug. 28, 1912. 

The alkali silicates are added in the form of alkali 
metasilicates, as the sole source of alkali. This is 
suitable for all kinds of glass, especially white glass. 

No. 273,707. Process for Making a Glass Resistant 
to Chemicals. Schott and Gen., June, 4, 
1914. 

This is made of silicic acid, clay, lime, boric acid and 
4-14 per cent alkali, in such mutual proportions that 
the entire quantity of clay and lime varies between 
half and five times the amount of boric acid. 







































































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